Surface modification of laser surface melting (LSM) was applied to the AM6OB magnesium alloy using a 10 kW continuous-wave CO2 laser. The microstructure, composition and corrosion resistance of AM6OB magnesium alloy after LSM treatment were investigated by using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) and corrosion tests, respectively. Results showed that the LSM treatment produced a continuous and homogeneous modified layer with refined grains, enriched Al element and redistributed intermetallic compounds on AM6OB alloy. The corrosion resistance of the AM6OB alloy was enhanced by the LSM treatment. The enhancement of the corrosion resistance was mainly attributed to the reduced corrosion susceptibility of Al enriched alpha-Mg matrix and the barrier effect of uniformly distributed beta-phase of the LSM modified layer. (C) 2015 Elsevier B.V. All rights reserved.