Abstract: Mg-Si-Zr alloys were prepared by powder metallurgy.The effect of Si content on microstructure and mechanical properties was investigated.The results indicate that the alloy powders were not mechanically alloyed during the ball milling process,Zr,Si and Mg still existed as elementary substances.The Mg2Si phase was formed after sintering,the amount of the new phase increased with the increase of Si content.The bending strength and hardness were also enhanced with the increase of Si content,and the Mg-6wt%Si-Zr alloy had maximum bending strength of 132 MPa.