A method of allocating frequency subbands in an ultrawideband (UWB) wireless communication system and an apparatus adopting the same are provided. The method of allocating frequency subbands to a device in a communication system, the method including: (a) determining whether usage of a first frequency band including upper frequency subbands is necessary; and (b) if it is determined that the usage of the first frequency band is necessary, not setting usage permission for the first frequency band to the device and not granting access to the first frequency band if a request for usage of the first frequency band is received from the device. When generation of a new piconet is necessary or generation of a new piconet is requested in a multi-piconet environment, since subbands of a high frequency group are allocated through negotiation, frequency resources are efficiently managed.