Abstract: A series of Controlled Diffusion Airfoils (CDA) has been developed for multistage compressor application.These airfoils are designed analytically to be shock free at transonic Mach numbers and to avoid the separation of the suction surface boundary layer for a range of inlet conditions necessary for stable compressor operation.From the results in the cascade testing,it has been demonstrated that CDA has higher critical Mach number,higher incidence range,and higher loading capability than standard series airfoils designed for equivalent aerodynamic requirements.By using these airfoils in single and multistage rig testing,the high efficiency,the high loading capability and good stage matching can be obtained,the costs can be reduced and the surge margin can be improved.The CDA profile shapes tend to have thicker leading and trailing edges than the conventional standard series profiles,which lead to the improvement of compressor durability.