In this study,CrN/Cr_2O_3 double-layered coatings with various thickness ratios of CrN vs Cr_2O_3 layer were prepared by arc ion plating technology.The influences of the thickness ratio of CrN vs Cr_2O_3 layer on the microstructural characteristics as well as the mechanical and tribological properties of the CrN/Cr_2O_3 doublelayered coatings were investigated.The corresponding mechanisms were also discussed.The results indicated that the insertion of CrN layer between the Cr_2O_3 layer and substrate can effectively decrease the internal stress level of the coating.With increasing the thickness ratio of CrN vs Cr_2O_3 layer,the surface roughness of double-layered coatings decreased gradually,which had a certain influence on the friction coefficient.In addition,the microhardness also declined gradually,the adhesive strength almost increased linearly,whereas the wear rate declined firstly and then increased slightly.As the thickness ratio was 2:1,the double-layered coating exhibited the best wear resistance. In this study, CrN / Cr 2 O 3 double-layered coatings with various thickness ratios of CrN vs Cr 2 O 3 layers were prepared by arc ion plating technology. These influences of the thickness ratio of CrN vs Cr 2 O 3 layers on the microstructural characteristics as well as the mechanical and tribological properties of the CrN / Cr_2O_3 doublelayered coatings were investigated. The results indicate that the insertion of CrN layer between the Cr_2O_3 layer and substrate can greatly reduce the internal stress level of the coating. Increasing the thickness ratio of CrN vs Cr 2 O 3 layer, the surface roughness of double-layered coatings decreased gradually, which had a certain influence on the coefficient of friction. In addition, the microhardness also declined gradually, the coating strength almost increased linearly, increased slightly. As the thickness ratio was 2: 1, the double-layered coating exhibited the best wear resistance.