A reinforcement is configured to have a corner portion corresponding to a corner portion of a side sill inner. Herein, the corner portion of the reinforcement forms a reinforcement ridgeline extending in a vehicle longitudinal direction. The reinforcement is provided such that the reinforcement ridgeline and a side-sill-inner upper ridgeline formed at a corner portion of the side sill inner overlap with each other over a range from a specified area where a wheel outward displaced in a vehicle collision is capable of contacting a side sill to a connection portion where a cross member connects to the side sill inner.