Centrifugal Compressors, which offer good flow stability, compact size and high stage pressure ratio, have been widely used in helicopter engines and sometime served as high pressure stage in small turbojet engines. In this paper, a method of developing a CFD model is presented for investigating the flow performance of a subsonic centrifugal compressor. The configuration used for the study is a subsonic centrifugal compressor which has a 60mm diameter impeller. A CFD modeling is carried out to obtain the performance and operational range of the compressor stage. The mesh independence studies were performed to provide confidence in the numerical results at operation speed. Particular emphasis is laid on the flow performance analysis with designed rotational speed of impeller.