A method for allocating a radio resource in a wireless communication system comprises defining a plurality of resource regions within a frame, a resource region comprising at least one orthogonal frequency division multiple access (OFDMA) symbol and at least one subchannel, configuring radio resource allocation information indicating which resource region selected from the plurality of resource regions is allocated to a UE, the radio resource allocation information comprising at least one resource region identifier (ID), a resource region ID indicating a resource region selected from the plurality of resource regions, and transmitting the radio resource allocation information to the UE.