This paper applied the Taguchi approach to investigate the effects of each polishing parameter and obtain the optimal processing conditions for CoCr alloy polishing. The polishing medium was 1μm diamond paste with Microcloth(polishing cloth). Surface finish parameter Sa was chosen as criterion for optimization. The experimental result indicates that the optimal polishing condition for CoCr alloy polishing is 5 0 of precess angle, 800 rpm of head speed, 0.2mm of tool offset and 1.5 bar of tool pressure. With this optimal condition, a confirmatory experiment was conducted. The surface roughness Sa reduced from initial 24nm to 7nm and reduction ratio was 72.5% which was very close to the estimated ratio 64%.