Mo coating was prepared on 45 steel by atmospheric plasma spraying. The microstructure, mechanical properties and wear resistance from room temperature to 300 ℃ of the Mo coating were investigated. The results show the microstructure of the Mo coating is dense and the coating and substrate bond well. The hardness of the Mo coating is 329.0 HV. With the increase of temperature, the friction coefficient and the wear rate of Mo coating increase. The friction coefficients of the Mo coating tested at room temperature and 300 ℃ are 0.52 and 1.14, respectively. The wear rate of the Mo coating tested at 300 ℃ 11.2×10-5 mm3/N·m, it is five times as that of room temperature. With the temperature increases, the splat de-lamination, oxidation wear and adhesive wear of Mo coating become more serious.