diff --git a/apps/system/test/marionette/lib/selection_helper.js b/apps/system/test/marionette/lib/selection_helper.js
@@ -0,0 +1,187 @@
+'use strict';
+
+var Actions = require('marionette-client').Actions;
+function SelectionHelper(client, element) {
+  this.client = client;
+  this.isInputOrTextarea =
+    (element.getAttribute('tagName') === 'INPUT' ||
+     element.getAttribute('tagName') === 'TEXTAREA');
+  this.element = element;
+  this.action = new Actions(this.client);
+}
+
+module.exports = SelectionHelper;
+
+SelectionHelper.prototype = {
+  get content() {
+    if (this.isInputOrTextarea) {
+      return this.element.getAttribute('value');
+    } else {
+      return this.element.text;
+    }
+  },
+
+  get selectedContent() {
+    return this.client.executeScript(this.getSelectionCmd() +
+      'return sel.toString();', [this.element]);
+  },
+
+  getSelectionCmd: function() {
+    if (this.isInputOrTextarea) {
+      return 'var sel = SpecialPowers.wrap(arguments[0]).editor.selection;' +
+             'sel = SpecialPowers.unwrap(sel);';
+    } else {
+      return 'var sel = window.getSelection();';
+    }
+  },
+
+  selectionRectList: function(idx) {
+    var cmd = this.getSelectionCmd() + 'return sel.getRangeAt(' + idx + ')' +
+      '.getClientRects();';
+    return this.client.executeScript(cmd, [this.element]);
+  },
+
+  rangeCount: function() {
+    var cmd = this.getSelectionCmd() + 'return sel.rangeCount;';
+    return this.client.executeScript(cmd, [this.element]);
+  },
+
+  /**
+   * Move caret by absolute position.
+   *       
+   * @param {Object} data
+   *                {caretA: {
+   *                   offset: {
+   *                      x: //poistion relative to element,
+   *                      y: //poistion relative to element
+   *                   },
+   *                 caretB: {
+   *                   offset: {
+   *                     x: //poistion relative to element,
+   *                     y: //poistion relative to element
+   *                   }
+   *                 }}
+   *
+   */
+  moveCaretByPosition: function(data) {
+    var caretPositions = this.selectionLocationHelper();
+    if (data.caretA) {
+      this.action.flick(this.element, caretPositions.caretA.x,
+        caretPositions.caretA.y + 15,
+        caretPositions.caretA.x + data.caretA.offset.x,
+        caretPositions.caretA.y + 15 + data.caretA.offset.y).perform();
+      this.client.wait(500);
+    }
+    if (data.caretB) {
+      this.action.flick(this.element, caretPositions.caretB.x,
+        caretPositions.caretB.y + 15,
+        caretPositions.caretB.x + data.caretB.offset.x,
+        caretPositions.caretB.y + 15 + data.caretB.offset.y).perform();
+    }
+  },
+
+  /**
+   * Move caret by word's position.
+   *       
+   * @param {Object} data
+   *                {caretA: {offset: //integer}, caretB: {offset //integer}}
+   *
+   */
+  moveCaretByWords: function(data) {
+    if (!this.isInputOrTextarea) {
+      console.log('only support input or textarea');
+      return;
+    }
+    var caretA = data.caretA;
+    var caretB = data.caretB;
+    var caretPositions = this.selectionLocationHelper();
+    var content = this.content;
+    var contentLength = content.length;
+
+    this.client.executeScript('arguments[0].setSelectionRange(' +
+      (caretA ? caretA.offset : 0) + ',' +
+      (contentLength + (caretB ? caretB.offset : 0)) + ' )',
+    [this.element]);
+
+    var newCaretPositions = this.selectionLocationHelper();
+
+    var eltSize = this.element.size();
+    this.action.tap(this.element, eltSize.width / 2, eltSize.height / 2)
+      .wait(2).press(this.element, eltSize.width / 2, eltSize.height / 2).
+      moveByOffset(0, 0).wait(2).release().perform();
+
+    var flickPosition = {};
+
+    if (caretA) {
+      flickPosition.caretA = {
+        offset: {
+          x: newCaretPositions.caretA.x - caretPositions.caretA.x,
+          y: newCaretPositions.caretA.y - caretPositions.caretA.y
+        }
+      };
+    }
+    if (caretB) {
+      flickPosition.caretB = {
+        offset: {
+          x: newCaretPositions.caretB.x - caretPositions.caretB.x,
+          y: newCaretPositions.caretB.y - caretPositions.caretB.y
+        }
+      };
+    }
+    this.moveCaretByPosition(flickPosition);
+  },
+
+  selectionLocationHelper: function(locationType) {
+    var rangeCount = this.rangeCount();
+    var firstRectList = this.selectionRectList(0);
+    var lastRectList = this.selectionRectList(rangeCount - 1);
+    var lastListLength = lastRectList.length;
+    var firstRect = firstRectList[0];
+    var lastRect = lastRectList[lastListLength - 1];
+    var originX = this.element.location.x;
+    var originY = this.element.location.y;
+    var startPos = 'left';
+    var endPos = 'right';
+    var startYOffset, endYOffset;
+
+    if (this.element.getAttribute('dir') === 'rtl') {
+      startPos = 'right';
+      endPos = 'left';
+    }
+    if (locationType === 'center') {
+      startYOffset = firstRect.height / 2;
+      endYOffset = lastRect.height / 2;
+    } else if (locationType === 'caret') {
+      startYOffset = firstRect.height + 5;
+      endYOffset = lastRect.height + 5;
+    } else {
+      startYOffset = endYOffset = 0;
+    }
+
+    return {
+      caretA: {
+        x: firstRect[startPos] - originX,
+        y: firstRect.top + startYOffset - originY
+      },
+      caretB: {
+        x: lastRect[endPos] - originX,
+        y: lastRect.top + endYOffset - originY
+      }
+    };
+  },
+
+  selectAll: function() {
+    var cmd;
+    if (this.isInputOrTextarea) {
+      cmd = 'var len = arguments[0].value.length; arguments[0].focus();' +
+        'arguments[0].setSelectionRange(0, len);';
+    } else {
+      cmd = 'var range = document.createRange();' +
+        'range.setStart(arguments[0].firstChild, 0);' +
+        'range.setEnd(arguments[0].lastChild, 0);' +
+        'var sel = window.getSelection();' +
+        'sel.removeAllRanges(); sel.addRange(range);';
+    }
+    this.client.executeScript(cmd, [this.element]);
+  }
+};
diff --git a/apps/system/test/marionette/lib/text_selection.js b/apps/system/test/marionette/lib/text_selection.js
@@ -53,6 +53,10 @@ TextSelection.prototype = {
     return location;
   },
 
+  switchToCurrentApp: function() {
+    this.client.apps.switchToApp(this._getDisplayedAppInfo().origin);
+  },
+
   /**
    * Get appWindow's id and origin of displayed app.
    * XXXXX: Since gecko is not ready yet, we need to simulate gecko dispatching
@@ -78,7 +82,14 @@ TextSelection.prototype = {
   },
 
   longPress: function(element) {
-    this.actions.tap(element, 10, 10).wait(2).longPress(element, 2).perform();
+    var eltSize = element.size();
+    this.longPressByPosition(element, eltSize/2, eltSize/2);
+  },
+
+  longPressByPosition: function(element, x, y) {
+    // Add moveByOffset to prevent contextmenu event be fired.
+    this.actions.tap(element, x, y).wait(2).press(element, x, y).
+      moveByOffset(0, 0).wait(2).release().perform();
   },
 
   pressCopy: function() {

diff --git a/apps/system/test/marionette/text_selection_test.js b/apps/system/test/marionette/text_selection_test.js