Abstract: AE41 magnesium alloys with different chemical compositions were prepared by adding 0.8%Ca and 0.2%-0.8%Si.The effects of Ca and different Si contents on the indention creep and microstructure of AE41 magnesium alloys were investigated by using OM,XRD,SEM,EDS and indentation creep testing.The results show that the creep property of AE41 alloy was improved by adding Ca,and improved further by adding Si,and the creep property of the alloys increased with the increase of Si content.The precipitated phases of AE41 magnesium alloy were rod phase Al11Nd3 and granular phase Al2Nd.There was bone phase Al2Ca precipitated after adding Ca,and the content of Al2Nd increased.Chinese script phase Mg2Si and complicated phases of the magnesium alloys appeared after further adding Si.The contents of rod,short-rod and particle phases increased with the increase of Si.The content of granular phase Al2Nd of AE41 alloy increased after creep,no new phase precipitated in the alloy contained Ca,but the content of Al2Ca decreased.The content of bone phase in the alloys containing Ca and Si decreased but the short-rod and particle phases increased during the creep deformation.