Abstract: Systematically checking calculations have been conducted to compare thesemiempirical loss models available in literatures for compressor rotors. It is found that neither the accuracy nor the scope of feasibility of these models can meet the demand of engineering prediction. A new model is developed on the basis of powered averaging of these models and employing the part-span damper loss model. The model can give quite accurate estimation for the spanwise loss distribution of a rotor, and has been successfully used in a streamline curvature method to predict the loss and flow field of an axial compressor rotor.