Disclosed are a system and a method for assigning ranging codes in a communication system. The communication system classifies rangings between a transmission unit and a reception unit of the broadband wireless access communication system into an initial ranging, a periodic ranging, a bandwidth request ranging, and a drop ranging. The communication system creates a first number of ranging codes used for the rangings and assigning a second number of ranging codes selected from the first number of ranging codes as drop ranging codes used for the drop ranging.