Abstract: Due to the poor pressing formability of AZ31 magnesium alloy sheets at room temperature, the magne-sium alloy sheets were obtained by rolling at different temperatures and their forming limit diagram (FLD) was drawn by the test of hemispherical punch bulging at room temperature. The effects of rolling temperature on the microstructure and room-temperature formability of the magnesium alloy sheets were analyzed. It is found that the room-temperature formability of the magnesium alloy sheets not only depends on grain size, but also depends on grain orientation. The weakening of the basal texture can significantly improve the performance of bulging forming, and grain size plays a decisive role on the room-temperature formability of the magnesium alloy sheets at the similar basal texture intensity.