In this paper, TaC x N 1 − x coatings deposited on 316L stainless steel (SS) by RF magnetron sputtering at various substrate temperatures ( T s), were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), scratch test and nanoindentation techniques. Then the corrosion resistance in phosphate buffered saline (PBS) and the hemocompatibility of the coating were further evaluated by potentiodynamic polarization, blood clotting test and platelet adhesion test. The substrate temperature ( T s) could significantly change the microstructure of TaC x N 1 − x coatings. When T s was less than 200 °C, the TaC x N 1 − x coatings were in amorphous condition, whereas when T s was increased to 200 °C, Ta 2CN phase was formed, exhibiting in the form of fine particulates with the crystallite sizes of about 6–9 nm. The appearance of the nanocrystalline Ta 2CN phase above 200 °C was associated with the pronounced increase in the hardness of TaC x N 1 − x coating from 10 GPa to over 30 GPa. The scratch test results demonstrated that TaC x N 1 − x coatings deposited above 200 °C exhibited good adhesion performance. The corrosion resistance of the 316L SS was improved significantly because of the deposited TaC x N 1 − x coatings. The blood clotting test and the platelet adhesion test results indicated that the TaC x N 1 − x coatings deposited at T s of 25 °C and 200 °C possessed better hemocompatibility than the coating deposited at T s of 400 °C.