Abstract: In order to improve the efficiency of CDMA network management, continuously improve the quality of network and satisfy the requirement of consumers, a decision support system for fault management was designed for CDMA network using an artificial intelligence technique which is called case-based reasoning. The overall framework and work flow of the system were given and some key technologies of system implementation were designed. The validity of the proposed system was examined in the test examples where the initial case base was established using some typical daily fault management recorders of a CDMA company and the new cases were generated using the other recorders. The experimental results show the proposed system can enhance the efficiency of CDMA network default management.