<p>A reinforcing member 51 is provided at a lower-outside corner 8a of a side-sill reinforcement 8 so as to extend in the vehicle longitudinal direction including a connection portion of the side sill 6 to a center pillar for straining deformation of the corner 8a. A deformation promoting portion 52 and/or 53 which is provided at an upper portion of the side-sill reinforcement 8 at a specified position which corresponds to the connection portion for prompting deformation of the upper portion of the side-sill reinforcement 8. Accordingly, a lower vehicle-body structure of a vehicle which can properly restrain the side sill and the center pillar from coming toward the vehicle inside at the vehicle side crash can be provided.</p>
