Abstract: This paper presents the flow measurement in the blade passage and downstream of a high turning controlled diffusion airfoil(CDA)cascade in details and the investigation of flow visualization on the endwall and blade surface.As a result,a thorough comprehension is obtained in respect of the flow in the blade passage especially in the endwall area,the vortex structure and of the effect of endwall boundary layer and secondary flow on the performance of the cascade.It is of great practical value in improving the flow conditions in the endwall area of a compressor and developing the second generation of the controlled diffusion airfoil.