In this study, we try to investigate the asymmetric rolling process affects microstructure, texture and formability of AZ31 Mg sheet. The deformation twins are clearly apparent, small and recrystallized grains are visible along some grain boundary and twinned regions in the as-rolled both samples. The symmetrically rolled sample tended to show peak inclined to the rolling direction. On the other hand, the asymmetrically rolled sample tended to show peak slightly inclined to the transverse direction. From the pole figure observation by EBSD, the intensity decrease of basal fiber texture after asymmetric rolling should be attributed to the severe shear strain induced during asymmetric process. The Erichsen value was measured to be 6.5 for asymmetrically rolled sample and 5.2 for symmetrically rolled sample.