Abstract: A vehicle rear body part includes a rear side member provided on both sides of a rear floor and a lower part of a back door opening section higher than the rear side member. The rear floor is divided into a main rear floor panel and left and right side rear floor panels with the rear side member placed therebetween. In the rear side member, rear side member upper panels are configured to close an opening in an upper part and joined to flanges on both the left and right sides. Upright sections are provided at rear ends of the rear side member upper panels. The upright sections are joined to a lower part of the opening section. The upper panels, the rear side member, and the floor panels and are joined in three layers in the flanges of the upper panels.