diff --git a/src/infiniteGrid.js b/src/infiniteGrid.js
index e3bfaa5..ee8f19f 100644
--- a/src/infiniteGrid.js
+++ b/src/infiniteGrid.js
@@ -5,8 +5,6 @@
 
 // jscs:disable validateLineBreaks, maximumLineLength
 eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, global, doc) {
-	var APPEND = BOTTOM = true;
-	var PREPEND = TOP = false;
 	"use strict";
 
 	/**
@@ -268,11 +266,11 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 		 */
 		layout: function(isRelayout, addItems, isAppend) {
 			isRelayout = typeof isRelayout === "undefined" ? true : isRelayout;
-			isAppend = typeof isAppend === "undefined" ? APPEND : isAppend;
+			isAppend = typeof isAppend === "undefined" ? true : isAppend;
 
 			// for except case.
 			if (!addItems && !isAppend) {
-				isAppend = APPEND;
+				isAppend = true;
 			}
 			this._waitResource(isRelayout, isAppend ? addItems : addItems.reverse(), isAppend);
 			return this;
@@ -309,11 +307,8 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 				v.position = self._getItemLayoutPosition(isRelayout, v, isAppend);
 			});
 			if (addItems && !isAppend) {
-				// addItems = addItems.sort(function(p, c) {
-				// 	return p.position.y > c.position.y;
-				// });
 				this.items = addItems.sort(function(p, c) {
-					return p.position.y > c.position.y;
+					return p.position.y - c.position.y;
 				}).concat(this.items);
 				
 				var y = this._getTopPositonY();
@@ -322,8 +317,8 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 					$.each(items, function(i, v) {
 						v.position.y -= y;
 					});
-					this._syncCols(TOP);
-					this._syncCols(BOTTOM);
+					this._syncCols(false);	// for prepending
+					this._syncCols(true);	// for appending
 				} 
 			}
 
@@ -357,7 +352,7 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 				this._isRecycling =
 				(this.items.length + $elements.length) >= this.options.count;
 			}
-			this._insert($elements, groupKey, APPEND);
+			this._insert($elements, groupKey, true);
 			return $elements.length;
 		},
 		/**
@@ -381,7 +376,7 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 			if ($elements.length > this._removedContent) {
 				$elements = $elements.slice(0, this._removedContent);
 			}
-			this._insert($elements, groupKey, PREPEND);
+			this._insert($elements, groupKey, false);
 			return $elements.length;
 		},
 		/**
@@ -412,12 +407,6 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 		_getTopItem: function() {
 			var item = null;
 			var min = Infinity;
-			// $.each(this._getColItems(TOP), function(i, v) {
-			// 	if (v && v.position.y < min) {
-			// 		min = v.position.y;
-			// 		item = v;
-			// 	}
-			// });
 			$.each(this.items, function(i, v) {
 				if (v && v.position.y < min) {
 					min = v.position.y;
@@ -443,7 +432,7 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 		getBottomElement: function() {
 			var item = null;
 			var max = -Infinity;
-			$.each(this._getColItems(BOTTOM), function(i, v) {
+			$.each(this._getColItems(false), function(i, v) {
 				if (v && v.position.y + v.size.height > max) {
 					max = v.position.y + v.size.height;
 					item = v;
@@ -546,7 +535,7 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 			}
 			if (isTop) {
 				targets = this.items.splice(0, idx);
-				this._syncCols(TOP);
+				this._syncCols(false); 	// for prepending
 			} else {
 				targets = idx === this.items.length ? this.items.splice(0) : this.items.splice(idx, this.items.length - idx);
 			}
@@ -611,8 +600,8 @@ eg.module("infiniteGrid", ["jQuery", eg, window, document], function($, ns, glob
 					applyDom && (v.el.style.top = v.position.y + "px");
 				});
 				applyDom && (this.el.style.height = this._getContainerSize().height + "px");
-				this._syncCols(TOP);	// for prepending
-				this._syncCols(BOTTOM);	// for appending
+				this._syncCols(false);	// for prepending
+				this._syncCols(true);	// for appending
 			}
 			return y;
 		},
diff --git a/test/manual/infiniteGrid.html b/test/manual/infiniteGrid.html
index 6ed5b6e..d697708 100644
--- a/test/manual/infiniteGrid.html
+++ b/test/manual/infiniteGrid.html
@@ -79,7 +79,8 @@
   <button class="append">append</button>
   <button class="prepend">prepend</button>
   <button class="fit">fit</button>
-  <button class="layout">layout</button><br>
+  <button class="layout">layout()</button><br>
+  <button class="layout_false">layout(false)</button><br>
   <button class="clear">clear</button>
   <button class="getStatus">getStatus</button>
   <button class="setStatus">setStatus</button><br>
@@ -88,22 +89,22 @@
 </div>
   <ul id="grid">
     <li class="item">
-      <div>테스트1</div>
+      <div>test1</div>
     </li>
     <li class="item">
-      <div>테스트2</div>
+      <div>test2</div>
     </li>
     <li class="item">
-      <div>테스트3</div>
+      <div>test3</div>
     </li>
     <li class="item">
-      <div>테스트4</div>
+      <div>test4</div>
     </li>
     <li class="item">
-      <div>테스트5</div>
+      <div>test5</div>
     </li>
     <li class="item">
-      <div>테스트6</div>
+      <div>test6</div>
     </li>
   </ul>
 <script>
@@ -127,13 +128,13 @@
 
 var oinst = $inst.infiniteGrid("instance");
 
-var HTML = '<li class="item"><div>테스트1</div></li><li class="item"><div>테스트2</div></li><li class="item"><div>테스트3</div></li><li class="item"><div>테스트4</div></li><li class="item"><div>테스트5</div></li><li class="item"><div>테스트6</div></li><li class="item"><div>테스트7</div></li>';
+var HTML = '<li class="item"><div>test1</div></li><li class="item"><div>test2</div></li><li class="item"><div>test3</div></li><li class="item"><div>test4</div></li><li class="item"><div>test5</div></li><li class="item"><div>test6</div></li><li class="item"><div>test7</div></li>';
 
 var tmpStatus = {};
 
 $("#grid").click(function(e) {
   var $el = $(e.target);
-  console.log(oinst.remove(e.target.parentNode));
+  oinst.remove(e.target.parentNode);
 });
 
 $("#controler").click(function(e) {
@@ -157,6 +158,8 @@
     oinst.fit();
   } else if ($el.hasClass("layout")) {
     oinst.layout();
+  } else if ($el.hasClass("layout_false")) {
+    oinst.layout(false);
   } else if ($el.hasClass("clear")) {
     oinst.clear();
   } else if ($el.hasClass("getStatus")) {
diff --git a/test/unit/infiniteGrid.test.html b/test/unit/infiniteGrid.test.html
index 6bed41d..7976a04 100644
--- a/test/unit/infiniteGrid.test.html
+++ b/test/unit/infiniteGrid.test.html
@@ -54,22 +54,22 @@ <h2 id="qunit-userAgent"></h2>
 	 </ul>
  	 <ul id="grid">
 		<li class="item">
-			<div>테스트1</div>
+			<div>test1</div>
 		</li>
 		<li class="item">
-			<div>테스트2</div>
+			<div>test2</div>
 		</li>
 		<li class="item">
-			<div>테스트3</div>
+			<div>test3</div>
 		</li>
 		<li class="item">
-			<div>테스트4</div>
+			<div>test4</div>
 		</li>
 		<li class="item">
-			<div>테스트5</div>
+			<div>test5</div>
 		</li>
 		<li class="item">
-			<div>테스트6</div>
+			<div>test6</div>
 		</li>
 	 </ul>
 	<!-- UI content End -->
diff --git a/test/unit/js/infiniteGrid.test.js b/test/unit/js/infiniteGrid.test.js
index f3e8156..4edbdea 100644
--- a/test/unit/js/infiniteGrid.test.js
+++ b/test/unit/js/infiniteGrid.test.js
@@ -328,6 +328,36 @@ QUnit.test("check a count of remove contents", function(assert) {
 QUnit.test("check item/element order and check removed parts", function(assert) {
 	var done = assert.async();
 
+	function getUniqueX(target) {
+		var temp = {};
+		var x = $(target).map(function(i, v) {
+			return v.position.x;	
+		}).each(function(i, v) {
+			if (!(v in temp)) {
+				temp[v] = v;
+			} 
+		});
+		
+		var ret = [];
+		for(var p in temp) {
+			ret.push(p);
+		}
+		return ret;
+	}
+
+	function getGroups(target) {
+		var x = getUniqueX(target);
+		var group = {};
+		$.each(x, function(i, v) {
+			group[v] = $.grep(target, function(gv) {
+				return gv.position.x === ~~v;
+			}).sort(function(p, c) {
+				return p.position.y - c.position.y;
+			});
+		});
+		return group;
+	}
+
 	//When
 	this.inst.on("layoutComplete",function(e) {
 		this.off();
@@ -338,6 +368,15 @@ QUnit.test("check item/element order and check removed parts", function(assert)
 			this.$el.children().slice(0,e.target.length).each( function(i, v) {
 				assert.equal($(v).data("prepend-index"), i, "check element order " + i);
 			});
+			var groups = getGroups(e.target);
+			for(var p in groups) {
+				$.each(groups[p], function(i, v) {
+					if (i > 0) {
+						assert.ok(v.position.y >=  groups[p][i-1].position.y, "it's greater than or equal to previous value");
+						assert.ok($(v.el).data("prepend-index") >=  $(groups[p][i-1].el).data("prepend-index"), "it's greater than or equal to previous value (data)");
+					}
+				})
+			}
 			assert.equal(e.isAppend, false, "prepend type");
 			done();
 		});
@@ -825,7 +864,6 @@ QUnit.test("if width is not changed, layout should be not called on resize event
 });
 
 
-
 QUnit.module("infiniteGrid private method Test", {
 	beforeEach : function() {
 		this.fakeWnd = {
@@ -857,4 +895,80 @@ QUnit.test("check _refreshViewport method", function(assert) {
 
 	// Then
 	assert.equal(inst._clientHeight, 200, "height is changed");
-});
\ No newline at end of file
+});
+
+
+QUnit.module("infiniteGrid layout(false) Test", {
+	beforeEach : function() {
+		this.inst = new eg.InfiniteGrid("#nochildren_grid", {
+			"count" : 30
+		});
+	},
+	afterEach : function() {
+		if(this.inst) {
+			this.inst.destroy();
+			this.inst = null;
+		}
+	}
+});
+
+QUnit.test("check a remove module", function(assert) {
+	var done = assert.async();
+	var beforePrependCols = null;
+	var beforePosition = null;
+	function getItem(items, position) {
+		return $.grep(items, function(v) {
+			return v.position.x === position.x && v.position.y === position.y;
+		});
+	}
+
+	// Given
+	// When
+	this.inst.on("layoutComplete",function(e) {
+		$.each(this._prependCols, function(i, v) {
+			assert.ok(v === 0, "prependCols values are zero");
+		});
+
+		this.off();
+		this.on("layoutComplete",function(e) {
+			// Given
+			beforePrependCols = this._prependCols.concat();
+			$.each(this._prependCols, function(i, v) {
+				assert.ok(v !== 0, "prependCols values aren't zero");
+			});
+
+			beforePosition = e.target[5].position;
+			var beforeItemLen = this.items.length;
+			var beforeElementLen = this.el.children.length;
+			var ret = getItem(this.items, beforePosition);
+			assert.equal(ret.length, 1, "only one");
+			
+			// When 
+			this.remove(e.target[5].el);
+			
+			// Then 
+			ret = getItem(this.items, beforePosition);
+			assert.equal(ret.length, 0, "nothing");
+			assert.equal(this.items.length, beforeItemLen-1, "remove items");
+			assert.equal(this.el.children.length, beforeElementLen-1, "remove DOM");
+
+			this.off();
+			this.on("layoutComplete",function(e) {
+				beforePrependCols = this._prependCols.concat();
+				$.each(this._prependCols, function(i, v) {
+					assert.equal(v, beforePrependCols[i], "equal before PrependCols");
+				});
+				// Then
+				var ret = getItem(this.items, beforePosition);
+				assert.equal(ret.length, 1, "relayout items");
+				done();
+			});
+			// Then
+			this.layout(false);
+		});
+		this.append(getContent("append", 25));	
+	});
+
+	// Then
+	this.inst.append(getContent("append", 25));
+});