Scratch test and friction test were performed to evaluate the internal and external interface behaviors of TiAlSiN coating,respectively.The critical compressive and shearing stress of coating failure during scratch test were calculated and the values are 30.84 MPa and 4.98 MPa respectively.The average friction coefficients of TiAlSiN coating against 2Crl2Ni4Mo3VNbN steel are 0.70 (sliding speed 50 m/min),0.63 (sliding speed 100 m/min),and 0.81(sliding speed 150 m/min).The elements diffusion was analyzed by EDS.Al and Si element of coating material diffuse to the steel disc,except Ti element.The oxidation decreases with the increase of sliding speed,but the adhesion increases with the increase of sliding speed.More Al element diffuses to the steel disc at the high sliding speed,but the diffusion of Si element keeps almost constant at different sliding speeds.