A Mo surface-modified layer onto Ti-5Zr-3Sn-5Mo-15Nb (TLM) substrate was prepared by plasma surface alloying technique. The microstructure, component distribution and micro-hardness of the Mo modified layer were analyzed. Contact angles with deionized water were measured, and wear behavior of the samples against corundum ball in simulated human body fluids was investigated. The results indicate an about 12 μm uniform Mo surface-modified layer was obtained, which was mainly composed of Mo phase. The surface hardness of Mo alloyed TLM increased significantly than that of untreated TLM, and the contact angle was lowered due to the generation of Mo layer and the increase of surface roughness, enhancing the surface wettability. More importantly, compared to as-received TLM alloy, the Mo modified alloy exhibited significant improvement of wear resistance, about 50 times, with lower friction coefficient.