Stretch formability of a Mn-free AZ31 Mg alloy rolled by the reverse cross-roll rolling was investigated at room temperature. The specimen rolled by the reverse cross-roll rolling showed superior stretch formability to that of the reference specimen. The (0002) plane texture of the specimen by the revere cross-roll rolling exhibited a low texture intensity and a circular spread of the basal pole from the ND compared with those of the reference specimen. It is suggested that the modification of basal texture by the reverse cross-roll rolling contributes to an activation of basal slip and twinning, resulting in an enhancement of the thickness-direction strain and tensile ductility. Besides, it is suggested that the coarse grain size of a Mn-free AZ31 alloy seems to enhance a stretch formability, because twins become easily generated during loading.