Abstract: An Mg-12Li-0.5Al-1Zn alloy ingot was prepared by melting in a high-vacuum electric induction furnace under argon atmosphere, and the effects of rolling deformations (30%,50%,70%) on microstructure and mechanical properties of the alloy were studied. The results show that with the increase of rolling deformation, the dynamic recrystallization happened and grains were refined, the tensile strength of the alloy increased and the elongation increased firstly and then decreased. When the rolling deformation was 70%, the tensile strength up to 166 MPa, and when the rolling deformation was 30%, the alloy owned the best plasticity with elongation of 50%. A large number of equiaxed dimples were found on room temperature tensile fracture of as-casted alloy and as-rolled alloys, and the fracture was ductile fracture.