Liquid-phase enhanced sintering of powder metallurgy (P/M) 316L stainless steel by addition of sintering aids was studied. 2%-8% of pre-alloyed Fe-Mo-B powder with two different particle sizes was added as sintering aids, and the specimens were sintered in vacuum at 1 200-1 350 ℃. The results show that the fine Fe-Mo-B powder (5-10 μm) has stronger activated effect. The sintered density increases with the increase in sintering aid content or sintering temperature. Warm compaction has a better effect on the control of dimensional precision of compacts. The prealloyed Fe-Mo-B powder deviated from Mo2FeB2 component can also be sintering aid of P/M 316L stainless steel.