A structure for mounting a battery onto an electric vehicle comprises: a pair of first body members extending in a longitudinal direction of the electric vehicle; a second body member, which connects the pair of first body members, extending in transversal direction of the electric vehicle; a battery case, which contains a battery, disposed between the pair of first body members and rear of the second body member; a plurality of first supporting members, which connect between the pair of first body members, fixed on a bottom of the battery case; and a second supporting member connecting between one of the first supporting members, which is disposed in the forefront of the battery case.