A method for improving communication quality in a CDMA system includes: storing, groups of quality control parameters for a BS covered by the BSC; adopting, by the BS and an MS covered by the BS, one of the groups of the quality control parameters to interact with each other when the MS sets up a call; monitoring, during the call, communication quality parameters reported by the BS or by the MS; and selecting one of the groups of the quality control parameters according to the communication quality parameters and transmitting the group of the quality control parameters selected to the BS or the MS. A system and a BSC are also disclosed by the embodiments of the present invention. The solution provided by the embodiments of the present invention may improve the communication quality in areas with weak signals.