Abstract:The multi-paths compression with sequential RD>ND>RD>ND(RD-Rolling Direction；ND-Normal Direction) was performed on the AZ31 magnesium alloy rolled sheet, and mechanical property of the previous deformation were studied, the electron backscatter diffraction (EBSD) technique was applied to track the grain orientation evolution during the above deformation, and activations of twin variants were analyzed. The results show that the deformation mechanism of {10-12} tensile twin ->{10-12} untwin ->{10-12} tensile twin and {10-12} untwin are sequentially related to each compression during the above deformation. The yielding strength was significantly decreased during the first untwining, but the yielding strengths were increased for both twinning and untwining during the following deformations, and there are not obvious differences between them. The activation of untwinning follows the Schmid criterion, and there is an obvious selective tendency for twin variant activation, twin variant t3 or t4 were activated to start the untwinning.