There is provided with a method for enabling a user equipment to perform a random access procedure in a wireless communication system. The method includes transmitting a random access preamble and receiving a random access response as a response to the random access preamble. The random access response is addressed by a random access identifier. The random access identifier is mapped to radio resources used for transmitting the random access preamble. The user equipment can immediately confirm its random access response and perform further efficient random access procedure.