Abstract: The alloyed layers of Mn-Al2O3 and Mn-Al2O3-NiWC were fabricated on 1Cr18Ni9Ti stainless steel by laser surface alloying to improve wear-corrosion resistance of stainless steel blades. High Mn-matrix composite coatings were in-situ fabricated which were composed of dendrites, eutectics and undissolved Al2O3 particles. Microstructure, wear and corrosion behavior of both the alloyed layers were investigated by orthogonal experiments. The results show that wear resistance is improved under all 9 sets of orthogonal parameters, while corrosion resistance is improved or decreased, varying with parameters. Wear resistance of the alloyed layers is influenced most by the addition amount of Al2O3, followed by scanning speed and laser power, while corrosion resistance is influenced inversely. Addition amount of Al2O3 affects the hard phase amount in the alloyed layers, determining hardness and wear resistance of the alloyed layers. Intergranular corrosion in combination with pitting in the grains and grain boundaries are observed in both kinds of alloyed layers. Corrosion resistance is determined by the various microstructure, phases, the unique chemical composition and corrosion characteristic of the phases and the homogeneity of the microstructure.