A method for allocating resources in a wireless communication system using Frequency Division Multiple Access (FDMA). The method includes dividing entire frequency resources into sub-bands each having a number of sub-channels, setting at least one sub-channel in each of the sub-bands as a wide-band resource, and providing the sub-band and wide-band information to mobile stations; and determining one of the sub-band resource and the wide-band resource as an allocated resource according to channel condition with a particular mobile station when there is a need for communication with the mobile station.