Self-piercing　riveting　(SPR)　has　been　used　to　join　similar　and　dissimilar　materials　for　vehicle　body　application.　In　order　to　understand　the　failure　mechanism　and　develop　a　method　to　estimate　the　shear　strength　of　SPR　similar　and　dissimilar　materials,　finite　element　modeling　was　conducted　in　this　study.　In　the　modeling,　the　contact　conditions　between　the　rivet　and　the　workpieces　were　taken　into　account　to　establish　the　failure　criteria　of　SPR　of　steel　and　aluminum　sheets.　It　was　found　that　the　failure　procedure　of　riveted　dissimilar　materials　was　different　from　that　of　riveted　similar　materials.　Furthermore,　the　experiments　were　conducted　to　validate　the　modeling　results.　It　was　shown　that　the　shear　strength　and　failure　mode　of　SPR　joints　were　in　agreement　with　the　modeling　results.　These　results　suggested　that　the　model　could　be　used　to　estimate　the　shear　strength　of　SPR　joints.　The　factors　influencing　the　failure　mode　and　shear　strength　of　SPR　joints　were　discussed　in　detail.　For　rivet　pull-out　mode,　the　rivet　open　angle　at　the　upper　sheet,　friction　coefficient　between　the　rivet　and　sheet,　and　the　yield　strength　of　the　substrate　were　the　key　factors.　For　sheet　tearing　mode,　failure　occurred　at　the　weaker　sheet　and　the　shear　strengths　mainly　depended　on　the　sheet　gage　and　strength　grade　of　the　weaker　sheet.