Abstract: An efficient calculation procedure was established which allowed the rapid computation of the total pressure distortion development through any combination of rotors,stators and clearances.The predictions of the response to steady circumferential pressure distortion of an axial flow compressor inlet guide vanes,rotor,stator and axial clearance were presented with four casing configurations:solid casing,circumferential groove casing,axial skewed slot casing,and blade angle slot casing.The affects of inlet guide vanes on response to steady circumferential pressure distortion of an axial flow compressor with four casing configurations were obtained.In comparison with solid casing,greatest attenuation of total pressure distortion and static pressure distortion through the rotor and stator of three casing treatment configurations were obtained.It is obvious that effective improvement in stall margin can be achieved with three casing treatment configurations under conditions of inlet circumferential pressure distortions.Appropriate design of casing treatment configurations for multistage axial flow compressors would be able to make axial compressors have high tolerant to inlet pressure distortions.