PURPOSE: To simplify the structure of a rear fender, by providing a door support step on a rear fender panel at its rear edge along a door space and conjoining the extended part of the inner part of a pillar to the reverse side of the door support step to form a closed cross-section to dipense with a reinforcing panel.

CONSTITUTION: A door support step 14 is provided on a rear fender panel 6 at its rear edge along a door space 12. The lower portion of the rear fender panel 6 including the lower part of the door support step 14 is a part of the outer portion 18 of a side sill 8. The inner portion 20 of a center is extended downwards so that an extended part 22 is provided. The extended part 22 is L-shaped. One side edge of the extended part 22 is conjoined to the outer rear surface of the door support step 14 and the other side edge is conjoined to the front edge of the rear fender panel 6 so that a closed cross-section is formed by the extended part and the door support step. The lower end of the extended prt 22 of the inner portion 20 of the center pillar is conjoined to the extended part 24' of a reinforcing panel 24 for the side sill 8.