Propose a new degradation call admission control(DCAC)scheme, which can be used in wideband code division multiple access communication system. So-called degradation is that non-real time call has the characteristic ofvariable bit rate, so decreasing its bit rate can reduce the load ofthe system, consequently the system can admit new call which should be blocked when the system is close to full load, therefore new call's access probability increases. This paper brings forward design project anddoessystemsimulation,simulation provesthatDCACcaneffectivelydecreasecalls'blockingprobabilityandincreasethe total number of the on-line users.