A body part for a motor vehicle with a positioning structure is provided. The body part includes an outer panel and an inner panel, and a backside of the outer panel is provided with a positioning structure to position the outer panel relative to the inner panel for their assembly, the positioning structure including a clamping seat configured to receive a shaft of a rack for positioning the outer panel thereon during manufacturing of the outer panel, and to be engaged in an opening of the inner panel to position the outer panel relative to the inner panel. The positioning structure combines the arrangements of both positioning holes and positioning ribs, thereby greatly enhancing the eligibility rate of spray painting and welding stability.