Abstract: A model to calculate axial flow compressor off design performance with uniform and radial distorted inlet flow is proposed,which takes into account variable specific heat and full radial equilibrium of the flow,including streamline curvature and radial gradients of total enthalpy and entropy.The efficiency is determined from a total pressure loss coefficient which is taken as the sum of a calculated reference loss coefficient and an off reference increment in loss coefficient.The correlated data are used for diffusion factors from 0 to 1 0 and Mach numbers from 0 to 1 6.The compression work or the total pressure ratio of a compressor is determined through the use of cascade element performance data concerning deviation angle.The model allows user to specify the mass flow at each blade row i.e.allows existence of flow bypass between two blade rows.Results for a five stage high speed compressor are analyzed in detail,and the comparison with the experimental data demonstrates that the model is reliable.