Abstract: Cam-tappet friction and wear has a major impact on engine performance. To study the wear and friction with different coatings of cam-tappet，the tribological performance test was conducted under three coating conditions，which are with WC wear-resistant coating，with NiCr-Cr₃C₂ anti-friction coating and without coating. In the same coating cases，the author conducted the test with specimens of different morphologies，obtained test curves and data of friction coefficient，wear quality and proportion. Based on the test data，it′s easy to know that NiCr-Cr₃C₂ coating on the cam-tappet does good to extend its life，besides，the surface roughness plays an important role in improving the friction characteristics.

Key words: cam-tappet, wear-resistant anti-friction coating, tribology, surface morphology