An aerodynamic design technique of a centrifugal impeller is developed. The design procedure consists of a preliminary design, a three-dimensional blade surface generation, a flow analysis of impeller passage and a compatibility analysis for the designed impeller. To get a higher efficiency, the backswept impeller which has a lean angle and a parabolic blade surface is designed. In the present analysis of flow in an impeller, an inviscid quasi-three-dimensional method and a viscous three-dimensional method are used. Compatibility of the designed impeller is decided with the results of the analyses. The quasi-three-dimensional method is easy to use, but limited to a few conditions in real application for the prediction of the actual flow in the impeller. Since the viscous three-dimensional method proved to predict the real flow in the impeller relatively well, it can be used as a means for the decision of compatibility of the designed impeller.