The joinability of three aluminium alloy sheets using a self-piercing rivet was evaluated from a finite element simulation and experiment. The self-piercing riveting is hopeful as replacement of spot resistance welding generally used for steel sheets, because it is not easy to apply the resistance welding to joining of three aluminium alloy sheets due to the high thermal conductivity. Defects in the riveting are categorized into the penetration through the lower sheet, the necking of the lower sheet and the short overlap of sheets to obtain optimum joining conditions. The penetration and the necking are caused by small total thickness. The short overlap tends to occur as the ratio of lower sheet and total thickness is small. In addition, the cross-tension test was simulated by the finite element method to evaluate the joint strength.