diff --git a/src/libecmaobjects/ecma-helpers.c b/src/libecmaobjects/ecma-helpers.c
index db5c5ab9a..8a67b7d8b 100644
--- a/src/libecmaobjects/ecma-helpers.c
+++ b/src/libecmaobjects/ecma-helpers.c
@@ -603,6 +603,19 @@ ecma_DuplicateEcmaString( ecma_ArrayFirstChunk_t *pFirstChunk) /**< first chunk
     return pFirstChunkCopy;
 } /* ecma_DuplicateEcmaString */
 
+/**
+ * Compare zero-terminated string to ecma-string
+ * 
+ * @return true - if strings are equal;
+ *         false - otherwise.
+ */
+bool
+ecma_CompareEcmaStringToEcmaString(const ecma_ArrayFirstChunk_t *string1_p, /* ecma-string */
+                                   const ecma_ArrayFirstChunk_t *string2_p) /* ecma-string */
+{
+  JERRY_UNIMPLEMENTED_REF_UNUSED_VARS( string1_p, string2_p);
+} /* ecma_CompareEcmaStringToEcmaString */
+
 /**
  * Compare zero-terminated string to ecma-string
  * 
diff --git a/src/libecmaobjects/ecma-helpers.h b/src/libecmaobjects/ecma-helpers.h
index 0d055ce37..a6a55c3fa 100644
--- a/src/libecmaobjects/ecma-helpers.h
+++ b/src/libecmaobjects/ecma-helpers.h
@@ -90,7 +90,7 @@ extern ecma_ArrayFirstChunk_t* ecma_NewEcmaString( const ecma_Char_t *pString);
 extern ssize_t ecma_CopyEcmaStringCharsToBuffer( ecma_ArrayFirstChunk_t *pFirstChunk, uint8_t *pBuffer, size_t bufferSize);
 extern ecma_ArrayFirstChunk_t* ecma_DuplicateEcmaString( ecma_ArrayFirstChunk_t *pFirstChunk);
 extern bool ecma_CompareZtStringToEcmaString( const ecma_Char_t *pString, const ecma_ArrayFirstChunk_t *pEcmaString);
-
+extern bool ecma_CompareEcmaStringToEcmaString(const ecma_ArrayFirstChunk_t *string1_p, const ecma_ArrayFirstChunk_t *string2_p);
 extern void ecma_FreeArray( ecma_ArrayFirstChunk_t *pFirstChunk);
 
 #endif /* !JERRY_ECMA_HELPERS_H */
diff --git a/src/libecmaoperations/ecma-comparison.c b/src/libecmaoperations/ecma-comparison.c
new file mode 100644
index 000000000..e6a87d455
--- /dev/null
+++ b/src/libecmaoperations/ecma-comparison.c
@@ -0,0 +1,105 @@
+/* Copyright 2014 Samsung Electronics Co., Ltd.
+ *
+ * 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.
+ */
+
+#include "ecma-comparison.h"
+#include "ecma-globals.h"
+#include "globals.h"
+
+/** \addtogroup ecma ---TODO---
+ * @{
+ * 
+ * \addtogroup ecmacomparison ECMA comparison
+ * @{
+ */
+
+/**
+ * ECMA abstract equality comparison routine.
+ *
+ * See also: ECMA-262 v5, 11.9.3
+ *
+ * @return true - if values are equal,
+ *         false - otherwise.
+ */
+bool
+ecma_abstract_equality_compare(ecma_Value_t x, /**< first operand */
+                               ecma_Value_t y) /**< second operand */
+{
+  const bool is_x_undefined = ecma_IsValueUndefined( x);
+  const bool is_x_null = ecma_IsValueNull( x);
+  const bool is_x_boolean = ecma_IsValueBoolean( x);
+  const bool is_x_number = ( x.m_ValueType == ECMA_TYPE_NUMBER );
+  const bool is_x_string = ( x.m_ValueType == ECMA_TYPE_STRING );
+  const bool is_x_object = ( x.m_ValueType == ECMA_TYPE_OBJECT );
+
+  const bool is_y_undefined = ecma_IsValueUndefined( y);
+  const bool is_y_null = ecma_IsValueNull( y);
+  const bool is_y_boolean = ecma_IsValueBoolean( y);
+  const bool is_y_number = ( y.m_ValueType == ECMA_TYPE_NUMBER );
+  const bool is_y_string = ( y.m_ValueType == ECMA_TYPE_STRING );
+  const bool is_y_object = ( y.m_ValueType == ECMA_TYPE_OBJECT );
+
+  const bool is_types_equal = ( ( is_x_undefined && is_y_undefined )
+                                || ( is_x_null && is_y_null )
+                                || ( is_x_boolean && is_y_boolean )
+                                || ( is_x_number && is_y_number )
+                                || ( is_x_string && is_y_string )
+                                || ( is_x_object && is_y_object ) );
+
+  if ( is_types_equal )
+  {
+    // 1.
+
+    if ( is_x_undefined
+         || is_x_null )
+    {
+      // a., b.
+      return true;
+    } else if ( is_x_number )
+    { // c.
+      ecma_Number_t x_num = *(ecma_Number_t*)( ecma_GetPointer(x.m_Value) );
+      ecma_Number_t y_num = *(ecma_Number_t*)( ecma_GetPointer(y.m_Value) );
+
+      TODO( Implement according to ECMA );
+
+      return (x_num == y_num);
+    } else if ( is_x_string )
+    { // d.
+      ecma_ArrayFirstChunk_t* x_str = (ecma_ArrayFirstChunk_t*)( ecma_GetPointer(x.m_Value) );
+      ecma_ArrayFirstChunk_t* y_str = (ecma_ArrayFirstChunk_t*)( ecma_GetPointer(y.m_Value) );
+
+      return ecma_CompareEcmaStringToEcmaString( x_str, y_str);
+    } else if ( is_x_boolean )
+    { // e.
+      return ( x.m_Value == y.m_Value );
+    } else
+    { // f.
+      JERRY_ASSERT( is_x_object );
+      
+      return ( x.m_Value == y.m_Value );
+    }
+  } else if ( ( is_x_null && is_y_undefined )
+              || ( is_x_undefined && is_y_null ) )
+  { // 2., 3.
+    return true;
+  } else
+  {
+    JERRY_UNIMPLEMENTED();
+  }
+} /* ecma_abstract_equality_compare */
+
+/**
+ * @}
+ * @}
+ */
diff --git a/src/libecmaoperations/ecma-comparison.h b/src/libecmaoperations/ecma-comparison.h
new file mode 100644
index 000000000..ed9e3654e
--- /dev/null
+++ b/src/libecmaoperations/ecma-comparison.h
@@ -0,0 +1,36 @@
+/* Copyright 2014 Samsung Electronics Co., Ltd.
+ *
+ * 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.
+ */
+
+#ifndef JERRY_ECMA_COMPARISON_H
+#define JERRY_ECMA_COMPARISON_H
+
+#include "ecma-globals.h"
+#include "ecma-helpers.h"
+
+/** \addtogroup ecma ---TODO---
+ * @{
+ * 
+ * \addtogroup ecmacomparison ECMA comparison
+ * @{
+ */
+
+extern bool ecma_abstract_equality_compare( ecma_Value_t x, ecma_Value_t y);
+
+/**
+ * @}
+ * @}
+ */
+
+#endif /* !JERRY_ECMA_COMPARISON_H */