A vehicle body panel structure, wherein an inner panel is disposed on the inner surface of an outer panel and a reinforcing inner panel is disposed on the inner surface of the inner panel. A plurality of recesses and projections forming a wave shape in cross section are formed on the inner panel and the reinforcing inner panel in the longitudinal direction of a vehicle body. These panels are joined to each other so that a closed cross section is formed of the inner panel and the reinforcing inner panel at the lower part of a joined part between the outer panel and the inner panel and a closed cross section is formed of the outer panel and the inner panel at the upper part of a joined part between the inner panel and the reinforcing inner panel. Accordingly, even if a head part moving distance is small, an HIC value can be lowered and uniformized at those portions other than an impact portion. Thus, even an Al alloy hood can sufficiently reduce the HIC value to contribute to a reduction in the weight of the vehicle body.