Abstract: A design method combining three dimensional direct analysis with two dimensional inverse design is applied to a high load transonic compressor stage.First,the flow structures of the available stage ATS 2 (Advomced Transonic Stage) were analyzed by the 3D N S code in order to find out the existing problems.Secondly,aerodynamic numerical optimization is used to redesign the hub of the original rotor.Furthermore,the new flow structure is checked by using the 3D code.The numerical analysis indicates that the optimized stage is improved both in flow structure and performances,especially the stall margin.