diff --git a/app/src/main/java/com/pileproject/drive/programming/visual/activity/ProgrammingActivityBase.java b/app/src/main/java/com/pileproject/drive/programming/visual/activity/ProgrammingActivityBase.java
index 8b2dbec..cb5989e 100644
--- a/app/src/main/java/com/pileproject/drive/programming/visual/activity/ProgrammingActivityBase.java
+++ b/app/src/main/java/com/pileproject/drive/programming/visual/activity/ProgrammingActivityBase.java
@@ -59,6 +59,7 @@ public abstract class ProgrammingActivityBase extends AppCompatActivity {
     private final String TAG = "NxtProgrammingActivity";
     private List<Button> mAddBlockButtons;
     private Button mExecButton;
+    private UndoAndRedoButtonsManager mButtonsManager;
     private ProgrammingSpaceManager mSpaceManager;
     private boolean mIsConnected = false;
 
@@ -108,8 +109,11 @@ protected void onPostCreate(Bundle savedInstanceState) {
     protected abstract Intent getIntentToExecute();
 
     private void findViews() {
+        mButtonsManager = new UndoAndRedoButtonsManager((Button) findViewById(R.id.programming_undoButton),
+                                                        (Button) findViewById(R.id.programming_redoButton));
         mSpaceManager = new ProgrammingSpaceManager(this,
-                                                    (BlockSpaceLayout) findViewById(R.id.programming_placingBlockSpaceLayout));
+                                                    (BlockSpaceLayout) findViewById(R.id.programming_placingBlockSpaceLayout),
+                                                    mButtonsManager);
         mAddBlockButtons = new ArrayList<>(NKINDS);
         mAddBlockButtons.add((Button) findViewById(R.id.programming_sequenceButton));
         mAddBlockButtons.add((Button) findViewById(R.id.programming_repetitionButton));
@@ -160,6 +164,7 @@ protected void onActivityResult(
                     String blockName = data.getStringExtra("block_name");
                     ArrayList<BlockBase> blocks = BlockFactory.createBlocks(howToMake, blockName);
                     mSpaceManager.addBlocks(blocks);
+                    mButtonsManager.checkButtonsWorkability();
                 }
                 break;
 
@@ -250,6 +255,7 @@ private void onDeleteAllBlocks() {
                                        @Override
                                        public void onClick(DialogInterface dialog, int which) {
                                            mSpaceManager.deleteAllBlocks();
+                                           mButtonsManager.checkButtonsWorkability();
                                        }
                                    })
                 .setNegativeButton(R.string.cancel, null)
@@ -348,4 +354,44 @@ public String getInputtedProgramName() {
             return mEditText.getText().toString();
         }
     }
+
+    /**
+     * The manager of Undo and Redo buttons.
+     * This check the workability of buttons and
+     * enable or disable them.
+     *
+     * @author <a href="mailto:tatsuyaw0c@gmail.com">Tatsuya Iwanari</a>
+     */
+    public class UndoAndRedoButtonsManager {
+        private Button mUndoButton;
+        private Button mRedoButton;
+
+        public UndoAndRedoButtonsManager(Button undoButton, Button redoButton) {
+            mUndoButton = undoButton;
+            mRedoButton = redoButton;
+
+            mUndoButton.setEnabled(false);
+            mUndoButton.setOnClickListener(new View.OnClickListener() {
+                @Override
+                public void onClick(View v) {
+                    mSpaceManager.undo();
+                    checkButtonsWorkability();
+                }
+            });
+
+            mRedoButton.setEnabled(false);
+            mRedoButton.setOnClickListener(new View.OnClickListener() {
+                @Override
+                public void onClick(View v) {
+                    mSpaceManager.redo();
+                    checkButtonsWorkability();
+                }
+            });
+        }
+
+        public void checkButtonsWorkability() {
+            mUndoButton.setEnabled(mSpaceManager.canUndo());
+            mRedoButton.setEnabled(mSpaceManager.canRedo());
+        }
+    }
 }
diff --git a/app/src/main/java/com/pileproject/drive/programming/visual/event/AddEvent.java b/app/src/main/java/com/pileproject/drive/programming/visual/event/AddEvent.java
new file mode 100644
index 0000000..b60b32b
--- /dev/null
+++ b/app/src/main/java/com/pileproject/drive/programming/visual/event/AddEvent.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2011-2015 PILE Project, Inc. <dev@pileproject.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.pileproject.drive.programming.visual.event;
+
+
+import com.pileproject.drive.programming.visual.block.BlockBase;
+import com.pileproject.drive.programming.visual.layout.BlockSpaceLayout;
+
+/**
+ * EventBase for the addition of block
+ *
+ * @author <a href="mailto:tatsuyaw0c@gmail.com">Tatsuya Iwanari</a>
+ * @version 1.0 4-June-2013
+ */
+public class AddEvent extends EventBase {
+
+    public AddEvent(int elementCount, int index) {
+        super(elementCount, index);
+    }
+
+    @Override
+    public EventBase undo(BlockSpaceLayout layout, int elementCount) {
+        // Get block name
+        String blockName = ((BlockBase) layout.getChildAt(mIndex)).getClass().getName();
+        layout.removeViewAt(mIndex); // Remove it
+
+        // Create a new DeleteNumDiff for Redo
+        EventBase diffForRedo = new DeleteEvent(elementCount, mIndex, blockName);
+        return diffForRedo;
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/pileproject/drive/programming/visual/event/ChangeNumberEvent.java b/app/src/main/java/com/pileproject/drive/programming/visual/event/ChangeNumberEvent.java
new file mode 100644
index 0000000..18b18cd
--- /dev/null
+++ b/app/src/main/java/com/pileproject/drive/programming/visual/event/ChangeNumberEvent.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2011-2015 PILE Project, Inc. <dev@pileproject.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.pileproject.drive.programming.visual.event;
+
+import com.pileproject.drive.programming.visual.block.BlockBase;
+import com.pileproject.drive.programming.visual.block.NumTextHolder;
+import com.pileproject.drive.programming.visual.layout.BlockSpaceLayout;
+
+/**
+ * EventBase for the number change of TextView attached to block
+ *
+ * @author <a href="mailto:tatsuyaw0c@gmail.com">Tatsuya Iwanari</a>
+ * @version 1.0 4-June-2013
+ */
+public class ChangeNumberEvent extends EventBase {
+    private int mOldNum;
+
+    public ChangeNumberEvent(int elementCount, int index, int oldNum) {
+        super(elementCount, index);
+
+        mOldNum = oldNum;
+    }
+
+    @Override
+    public EventBase undo(BlockSpaceLayout layout, int elementCount) {
+        BlockBase block = (BlockBase) layout.getChildAt(mIndex);
+
+        // Get current number of TextView
+        int curNum = ((NumTextHolder) block).getNum();
+        ((NumTextHolder) block).setNum(mOldNum); // Set old number to TextView
+
+        // Create a new ChangeNumberEvent for Redo
+        EventBase diffForRedo = new ChangeNumberEvent(elementCount, mIndex, curNum);
+
+        return diffForRedo;
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/pileproject/drive/programming/visual/event/DeleteEvent.java b/app/src/main/java/com/pileproject/drive/programming/visual/event/DeleteEvent.java
new file mode 100644
index 0000000..3be33e1
--- /dev/null
+++ b/app/src/main/java/com/pileproject/drive/programming/visual/event/DeleteEvent.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2011-2015 PILE Project, Inc. <dev@pileproject.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.pileproject.drive.programming.visual.event;
+
+import android.view.ViewGroup;
+
+import com.pileproject.drive.programming.visual.block.BlockBase;
+import com.pileproject.drive.programming.visual.block.BlockFactory;
+import com.pileproject.drive.programming.visual.layout.BlockSpaceLayout;
+
+/**
+ * EventBase for the delete of a block
+ *
+ * @author <a href="mailto:tatsuyaw0c@gmail.com">Tatsuya Iwanari</a>
+ * @version 1.0 4-June-2013
+ */
+public class DeleteEvent extends EventBase {
+    private String mBlockName;
+
+    public DeleteEvent(int elementCount, int index, String name) {
+        super(elementCount, index);
+
+        mBlockName = name;
+    }
+
+    @Override
+    public EventBase undo(BlockSpaceLayout layout, int elementCount) {
+        // Recreate block
+        BlockBase block = BlockFactory.createBlocks(BlockFactory.UNDO, mBlockName).get(0);
+
+        // Attach it to layout
+        layout.addView(block, mIndex,
+                       new BlockSpaceLayout.LayoutParams(
+                               ViewGroup.LayoutParams.WRAP_CONTENT,
+                               ViewGroup.LayoutParams.WRAP_CONTENT));
+
+        // Create a new AddNumDiff for Redo
+        EventBase diffForRedo = new AddEvent(elementCount, mIndex);
+        return diffForRedo;
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/pileproject/drive/programming/visual/event/EventBase.java b/app/src/main/java/com/pileproject/drive/programming/visual/event/EventBase.java
new file mode 100644
index 0000000..67f05a5
--- /dev/null
+++ b/app/src/main/java/com/pileproject/drive/programming/visual/event/EventBase.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2011-2015 PILE Project, Inc. <dev@pileproject.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.pileproject.drive.programming.visual.event;
+
+
+import com.pileproject.drive.programming.visual.layout.BlockSpaceLayout;
+
+/**
+ * Base class of EventBase for undo and redo
+ *
+ * @author <a href="mailto:tatsuyaw0c@gmail.com">Tatsuya Iwanari</a>
+ * @version 1.0 4-June-2013
+ */
+public abstract class EventBase {
+    protected final int mElementCount;
+    protected final int mIndex;
+
+    protected EventBase(int elementCount, int index) {
+        mElementCount = elementCount;
+        mIndex = index;
+    }
+
+    public int getElementCount() {
+        return mElementCount;
+    }
+
+    public int getIndex() {
+        return mIndex;
+    }
+
+    /**
+     * Undo method
+     *
+     * @param layout       Layout that has blocks
+     * @param elementCount Number that shows how many UNDOs should be done at once
+     * @return
+     */
+    public abstract EventBase undo(BlockSpaceLayout layout, int elementCount);
+}
diff --git a/app/src/main/java/com/pileproject/drive/programming/visual/event/MoveEvent.java b/app/src/main/java/com/pileproject/drive/programming/visual/event/MoveEvent.java
new file mode 100644
index 0000000..e4576c7
--- /dev/null
+++ b/app/src/main/java/com/pileproject/drive/programming/visual/event/MoveEvent.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2011-2015 PILE Project, Inc. <dev@pileproject.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.pileproject.drive.programming.visual.event;
+
+import android.view.View;
+
+import com.pileproject.drive.programming.visual.layout.BlockSpaceLayout;
+
+
+/**
+ * EventBase for the move of block
+ *
+ * @author <a href="mailto:tatsuyaw0c@gmail.com">Tatsuya Iwanari</a>
+ * @version 1.0 4-June-2013
+ */
+public class MoveEvent extends EventBase {
+    private int mOldX, mOldY;
+
+    public MoveEvent(int elementCount, int index, int oldX, int oldY) {
+        super(elementCount, index);
+        mOldX = oldX;
+        mOldY = oldY;
+    }
+
+    @Override
+    public EventBase undo(BlockSpaceLayout layout, int elementCount) {
+        View view = layout.getChildAt(mIndex); // Get view
+
+        // Get current position of View and move
+        int curX = view.getLeft();
+        int curY = view.getTop();
+        view.layout(mOldX, mOldY, mOldX + view.getWidth(), mOldY + view.getHeight());
+
+        // Create New MoveEvent for Redo
+        EventBase diffForRedo = new MoveEvent(elementCount, mIndex, curX, curY);
+
+        return diffForRedo;
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/pileproject/drive/programming/visual/layout/ProgrammingSpaceManager.java b/app/src/main/java/com/pileproject/drive/programming/visual/layout/ProgrammingSpaceManager.java
index 51c1781..a0f5533 100644
--- a/app/src/main/java/com/pileproject/drive/programming/visual/layout/ProgrammingSpaceManager.java
+++ b/app/src/main/java/com/pileproject/drive/programming/visual/layout/ProgrammingSpaceManager.java
@@ -20,6 +20,7 @@
 import android.content.Context;
 import android.content.DialogInterface;
 import android.content.DialogInterface.OnClickListener;
+import android.util.Log;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.View.OnLongClickListener;
@@ -31,14 +32,21 @@
 import android.widget.TextView;
 
 import com.pileproject.drive.R;
+import com.pileproject.drive.programming.visual.activity.ProgrammingActivityBase;
 import com.pileproject.drive.programming.visual.block.BlockBase;
 import com.pileproject.drive.programming.visual.block.NumTextHolder;
+import com.pileproject.drive.programming.visual.event.AddEvent;
+import com.pileproject.drive.programming.visual.event.ChangeNumberEvent;
+import com.pileproject.drive.programming.visual.event.DeleteEvent;
+import com.pileproject.drive.programming.visual.event.EventBase;
+import com.pileproject.drive.programming.visual.event.MoveEvent;
 import com.pileproject.drive.util.Range;
 import com.pileproject.drive.util.Unit;
 import com.pileproject.drive.view.NumberSelectSeekBarView;
 import com.pileproject.drive.view.NumberSelectView;
 
 import java.util.ArrayList;
+import java.util.Stack;
 
 /**
  * Manager of BlockSpaceLayout This helps users make programs.
@@ -49,6 +57,9 @@
 public class ProgrammingSpaceManager extends BlockSpaceManager {
     private final int WC = ViewGroup.LayoutParams.WRAP_CONTENT;
     private final String TAG = "ProgrammingSpaceManger";
+    private Stack<EventBase> mLogForUndo = null;
+    private Stack<EventBase> mLogForRedo = null;
+    private ProgrammingActivityBase.UndoAndRedoButtonsManager mButtonsManager;
     public final OnTouchListener mMoveBlock = new OnTouchListener() {
         int currentX; // The left position of this view (x coordinate)
         int currentY; // The top position of this view (y coordinate)
@@ -93,10 +104,28 @@ public boolean onTouch(View view, MotionEvent event) {
 
                 // Finished Moving
                 case MotionEvent.ACTION_UP:
+                    int elementCount = 1;
+
+                    EventBase diff = new MoveEvent(elementCount++, mLayout.indexOfChild(view), originX, originY);
+                    mLogForUndo.push(diff);
+
                     // This view will be removed if it is on the trash box
                     if (mLayout.isOnTrash(view)) {
+                        if (view instanceof NumTextHolder) {
+                            // Get old value
+                            int oldNum = ((NumTextHolder) view).getNum();
+
+                            diff = new ChangeNumberEvent(elementCount++, mLayout.indexOfChild(view), oldNum);
+                            mLogForUndo.push(diff);
+                        }
+                        diff = new DeleteEvent(elementCount++, mLayout.indexOfChild(view), view.getClass().getName());
+                        mLogForUndo.push(diff);
                         mLayout.removeView(view);
                     }
+                    mLogForRedo.clear();
+
+                    // Check Undo/Redo buttons' workability
+                    mButtonsManager.checkButtonsWorkability();
                     break;
             }
             return true;
@@ -125,8 +154,66 @@ private void moveViewWithinItsParent(
         }
     };
 
-    public ProgrammingSpaceManager(Context context, BlockSpaceLayout layout) {
+    public ProgrammingSpaceManager(
+            Context context,
+            BlockSpaceLayout layout,
+            ProgrammingActivityBase.UndoAndRedoButtonsManager buttonsManager) {
         super(context, layout);
+        mButtonsManager = buttonsManager;
+
+        mLogForUndo = new Stack<>();
+        mLogForRedo = new Stack<>();
+    }
+
+    public boolean canUndo() {
+        return !mLogForUndo.empty();
+    }
+
+    public boolean undo() {
+        if (mLogForUndo.empty()) {
+            return false;
+        }
+
+        int elementCount = mLogForUndo.peek().getElementCount();
+
+        // Undo for elementCount times
+        for (int i = 0; i < elementCount; i++) {
+            EventBase diff = mLogForUndo.pop();
+
+            Log.d(TAG, diff.getClass().getSimpleName());
+
+            EventBase forRedo = diff.undo(mLayout, elementCount);
+            if (diff instanceof DeleteEvent) {
+                BlockBase block = (BlockBase) mLayout.getChildAt(forRedo.getIndex());
+                setListeners(block);
+            }
+            mLogForRedo.push(forRedo);
+        }
+        return true;
+    }
+
+    public boolean canRedo() {
+        return !mLogForRedo.empty();
+    }
+
+    public boolean redo() {
+        if (mLogForRedo.empty()) {
+            return false;
+        }
+
+        int elementCount = mLogForRedo.peek().getElementCount();
+
+        // Undo for elementCount times
+        for (int i = 0; i < elementCount; i++) {
+            EventBase diff = mLogForRedo.pop();
+            EventBase forUndo = diff.undo(mLayout, elementCount);
+            if (diff instanceof DeleteEvent) {
+                BlockBase block = (BlockBase) mLayout.getChildAt(forUndo.getIndex());
+                setListeners(block);
+            }
+            mLogForUndo.push(forUndo);
+        }
+        return true;
     }
 
     private void setListeners(BlockBase block) {
@@ -151,12 +238,19 @@ public void addBlocks(ArrayList<BlockBase> blocks) {
             mLayout.addView(block, new LayoutParams(WC, WC));
 
             block.setAnimation(alpha);
+
+            // Create new AddEventBase
+            EventBase diff = new AddEvent(blocks.size(), mLayout.indexOfChild(block));
+            mLogForUndo.push(diff);
         }
+        mLogForRedo.clear();
     }
 
     @Override
     public void deleteAllBlocks() {
         super.deleteAllBlocks();
+        mLogForUndo.clear();
+        mLogForRedo.clear();
     }
 
     class OnTouchNumTextListener implements OnLongClickListener {
@@ -199,6 +293,15 @@ public void onClick(DialogInterface dialog, int which) {
 
                     // Set new value
                     mParent.setNum(newNum);
+
+                    // Create ChangeNumberEvent
+                    EventBase diff = new ChangeNumberEvent(1, mLayout.indexOfChild((View) mParent), oldNum);
+
+                    mLogForUndo.push(diff);
+                    mLogForRedo.clear();
+
+                    // Check Undo/Redo buttons' workability
+                    mButtonsManager.checkButtonsWorkability();
                 }
             });
             dialog.show();
diff --git a/app/src/main/res/layout/content_programming.xml b/app/src/main/res/layout/content_programming.xml
index fc43c02..8b9a95d 100644
--- a/app/src/main/res/layout/content_programming.xml
+++ b/app/src/main/res/layout/content_programming.xml
@@ -72,7 +72,7 @@
         android:id="@+id/programming.spaceLayout"
         android:layout_width="match_parent"
         android:layout_height="fill_parent"
-        android:layout_above="@+id/programming.execButtonLayout"
+        android:layout_above="@+id/programming.redoAndUndoButtonsLayout"
         android:layout_below="@id/programming.addBlockButtonsLayout"
         android:orientation="horizontal">
 
@@ -85,6 +85,29 @@
 
     </FrameLayout>
 
+    <!-- Redo, Undo buttons -->
+
+    <LinearLayout
+        android:id="@+id/programming.redoAndUndoButtonsLayout"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_above="@+id/programming.execButtonLayout">
+
+        <Button
+            android:id="@+id/programming.undoButton"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:text="@string/programming.undo" />
+
+        <Button
+            android:id="@+id/programming.redoButton"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:text="@string/programming.redo" />
+    </LinearLayout>
+
     <!-- button to execution display -->
 
     <LinearLayout