In this paper, the TaCx coating with thickness around 1.2 μm was prepared by radio frequency magnetron sputtering technique on the 316L stainless steel substrate to improve its hemocompatibility. The structure and morphology of the coating were characterized by XRD and SEM. The XRD results indicated that TaCx, as a new species, appeared on the surface of the 316L stainless steel substrate. SEM images showed that the surface morphology of the TaCx coating was uniform and dense. The mechanical characteristics of the coating were measured by nanoindentation, giving a nanohardness of 13 GPa and a Young’s modulus of 210 GPa. The adhesion strength of the TaCx coating to 316L stainless steel depended on the sputtering bias voltages and increased for a higher bias voltage. The hemocompatibility of the TaCx coating, as evaluated by platelet adhesion tests, was compared to that of the bare 316L stainless steel. The results indicated that the hemocompatibility of 316L stainless steel with TaCx coating was significantly improved as compared to the original one.