Abstract: The post-stall behaviors,such as surge and rotating stall,of a three-st age compressor are simulat ed based on an one-dimensional unsteady model for the dynamic response of compression system.The variations of the annular average parameters, i.e.velocity,pressure,temperature and flow coefficient,can be obtained from the simulation. The stall types can be identified by these parameters vs.time.In addition,the effect of parameter"B",proposed by E.M.Greitzer,is analyzed.