Abstract: Compressor is the heart of refrigerator and the fracture of the valve in compressor will bring about severe failure of cold-producing system.The characteristics and mechanism of valve fracture are investigated in the paper by means of optical microscopy,scanning electronic microscopy(SEM),metalligraphic microscopy,microhardness,surface stress and elemental analysis.The SEM analysis indicates that the valve failure is fatigue fracture,and there exist clear fatigue expansion regions and many crack originals in the fracture.The chemical composition and micro structure of the valve are qualified.The local damage on the valve surface is liable to the fracture,and the shape of the valve and plastic flat gasket have impact on the valve fracture.On the basis of the above analysis,some quality improvement measures are presented,and good result is received.