CrCN coatings were deposited using the multi-arc ion plating with different C2H2 flow rates. Microstructures, mechanical and tribological performances were systematically investigated. The results showed that the peak intensity correlated to Cr7C3 crystal phase became stronger when the flow rates increased from 0 to 15sccm, whereas, it was decreased when the C2H2 flow rate increased to 30sccm. The hardness increased to 32.5GPa due to formation of Cr7C3 phase and amorphous CNx at 10sccm. CrCN coatings deposited at 10–15sccm exhibited a better comprehensive performance, indicating their potential application as a protective coating for tribo-components in seawater.