Abstract: The latest internal and external research status of nano-reinforcement applied to magnesium matrix composites is reviewed.The effects of SiC,Y2O3,Al2O3,AlN nanoparticles and carbon nanotubes(CNTs) on the microstructure and mechanical properties of magnesium matrix composites are especially discussed.And the strengthen mechanism is also concluded and summarized.Based on the problems included in the study of nano-reinforcement reinforced magnesium matrix composites,some research orientations in the future are suggested.