The energy dissipation per load cycle in a riveted lap joint of aircraft structure was investigated as structural damping characteristics. The specimens were riveted lap joints with 2024-T3 clad skins and NAS-1097 rivets in this research. Energy dissipation per cycle under in-plane shear loading (DS), and under in-plane tensile and shear loading (DTS) were measured on specimens using an extensometer, a tensile test machine, and rail shear jigs for riveted lap joint specimens. FE-simulations were conducted in order to estimate rivet transferring loads in specimen, and an area of slip surface (m) on interfacial surface of riveted lap joint. The experimental results under varying load condition on specimens showed that DS and DTS are proportional 3-powered the in-plane load ranges. The FE-simulations results showed that relationship between m and load applied to a riveted lap joint is linear, and the area of slip surface is associated with the amount of rivet transferring load, regardless of load direction. The discussions from these results showed that the energy dissipation in a riveted lap joint under in-plane tensile and shear loading can be estimated from the amount of in-plane tensile and shear loads applied to a riveted lap joint.