The microstructure and wear resistance of a laser surface alloyed Al-Mg-Si with Co alloy powder were investigated. The experimental results indicate that a porosity-free zone can be generated but some cracks appear after laser surface alloying (LSA). In this investigation, two regions, A (surface region) and B (bottom region), are observed in the pool. Al 9 Co 2 particles with a network structure are present in region A and block-like Al 13 Co 4 particles are distributed in region B. The hardness of the LSA specimens is three to nine times higher than that of the Almatrix. The high hardness of LSA specimens cause them to exhibit excellent sliding wear performance so they have a lower friction coefficient and wear rate. Notably, the critical temperature of the sliding wear resistance of the LSA specimen exceeds that of the Al-matrix by approximately 50 K
