Abstract: Aluminum-bronze alloy was surfaced on low carbon steel with reverse polarity weak plasma arc under different welding conditions.The microstructures of surfacing layer were studied by means of optical metallograghy,SEM and XRD,and the hardness and wear extent of the layer were measured.The results show that the bond between surfacing weld and base metal is metallurgical bond,and the surfacing layer has a low rate of dilution.The wear resistance of the layer has been significantly improved when α-phase has compact structure or α-phase is in reticular distribution along grain boundary.The analysis of the abrasion mechanism between surfacing weld metal and 45 steel under different welding conditions indicates that the wear resistance of the layer is related to microstructure of alloy,hardness and the feature of friction pairs.