Abstract: The inlet flow distortion effects in a five stage compressor have been investigated experimentally.The inlet total pressure distortion and swirl distortion have been generated by inserting perforated screens and guide vanes respectively into the compressor inlet duct.It has been found that both inlet total pressure distortion and swirl distortion have strong effects on the performance and stability of the compressor.With the increase in the angular width of the low inlet total pressure,both the pressure ratio and efficiency of the compressor decrease, and the loss of surge pressure ratio of the compressor increases when the distorted sector angle less than 60°.The inlet swirl distortion has a stronger effect on the loss of surge pressure ratio than the influence of inlet total pressure distortion.