In this study, about 400 nm thick BCN films with different compositions were grown by reactive DC magnetron sputtering of a B4C target by varying the N-2/Ar proportion in the sputtering gas from 0 to 50%. The microstructures of the films were determined by FE-SEM. The chemical composition was determined by electron probe microanalyser (EPMA). The crystallinity of the films was studied by grazing incidence XRD analyses. FTIR was used to determine the chemical bonding structures. The elemental depth profiles of the films were obtained from SIMS measurements. Nanoindentation and wear tests were used to determine the mechanical and tribological properties. Hardness, elastic modulus and wear rates of BCN films were significantly decreased with the increase of nitrogen in the coating composition. The results demonstrated that thin films in the ternary triangle B-C-N with tailored properties can easily be deposited by reactive DC magnetron sputtering with varying N-2 flow rates.