A systematic study on the three dimensional (3D) prototyping of cobalt-chromium alloys are carried out by using a self-developed laser melting equipment. The optimizations of properties which involve the surface roughness, surface morphology, relative density, hardness of the workpieces are further discussed. Results show that melting shrinkage and thickness accumulation of the powder layer are two important factors to affect the forming quality; the smaller of the surface roughness cumulative effect, the less pore are observed, which lead to a high relative density; Furthermore, macro-hardness of the part has a significant dependence on relative density. The relative density of 98.04% and the macro-hardness of 40HRC under the optical process parameters are obtained, conforming to American society of testing materials (ASTM) standards.