The effects of solid solution and aging treatment on the microstructure and mechanical properties of the Mg-10 Gd-2 Y-0.5 Zn-0.5 Zr experimental magnesium alloy were investigated. The results reveal that the microstructure of the as-cast alloy is mainly composed of α-Mg

Mg

5

（Gd

Y）

Mg

24

（Y

Gd）

5

and Mg

12

（Gd

Y）Zn phases

and the solid solution and aging treatment have no obvious effect on the type of the alloying phases

however the solid solution temperature has a great effect on the amount of the Mg

12

（Gd

Y）Zn phase

and the new Mg

12

（Gd

Y）Zn phase is precipitated during the aging treatment. In addition

after being solutionized at 480 ℃×24 h for the experimental alloy

the tensile strength

yield strength and elongation at room temperature are obviously improved

especially the elongation reaches 15.3%. Furthermore

after being aged at 200 ℃×24 h

the tensile strength

yield strength and elongation of the alloy at room temperature reach 278 MPa

235 MPa and 5.5%

respectively.