WC-Co cermet has wide applications in machinery industries as a wear-resisitance coating.The fabrication of Nanostructured coatings would be more encouraging in tribological surface engineering.In this paper,the nanostructured and conventional WC-Co coatings were depsited on 1Cr18Ni9Ti stainless steel substrate using an atmospheric plasma spray technique.Their microstructures and tribology properties in water environment were comparatively invesgated.It was found that the as-sprayed WC-Co coating were composed ofWC as the major phase and W2C,WC1-x,and W3Co3C as the minor phase.The nanostructured WC-Co coating had much higher hardness and more uniform microstructure.In water environment,beth the nanostructured and conventional WC-Co coatings had the similar friction coefficient under the same conditions.