WC-Co coatings were sprayed by high-velocity oxygen fuel (HVOF) on bearing steels. The coating consisted of a high volume fraction of WC particles in cobalt matrix. The hardness of WC-Co coating was 60% higher than that of the bearing steel. The friction coefficients of WC-Co coating and bearing steel sliding against mild steel were tested with lithium grease and water lubrication. The friction results indicated that the friction coefficient increased with increasing loads. The friction coefficient of WC-Co coating was lower than that of bearing steels no matter with grease lubrication or with water lubrication.