Abstract: The conta fatiguc resistance of several overlaying alloys had been compared, by rolling-sliding tests, and a new Fc-Mn alloy showed the best resistance among the different alloys. The service life of this alloy was found to. be longer than 1×10⁷ under the condition of σ_j=1560 MPa. The mechanism of the good contact fatigue resistance of the alloy was investigated. It is considered that the strain-induced martensitic transformation, from γ to α' and the precipitation of M₃C carbide particles increase the strength of the material effectively,and impede the continuous plastic deformation. As the huge reserve of toughness in the austenite surrounding the martensite can decrease the propagation rate of cracks, so the service life is increased. One of the advantages of this overlaying alloy is that the heat treatment for the overlaid surface can be saved because the strength needed can be obtained in the running-in process through effective work-hardening.