In this paper, we propose an improved interference cancellation (IC) scheme for CDM-FH-OFDMA system, which is the extension of frequency-hopping orthogonal frequency division multiplexing access (FH-OFDMA) with code division multiplexing (CDM). Because of the application of CDM, the multi-code interference (MCI) becomes severe and inevitable under dispersive channel condition. In order to mitigate MCI and improve system performance, the receiver with interference cancellation scheme should be applied. Simulation results are presented for turbo coded systems and proved that the improved IC scheme can achieve much better performance