Interior　shear　keys　commonly　serve　as　structural　fuses　to　control　damage　in　substructures　under　seismic　loads.　To　evaluate　the　seismic　capacity　of　interior　shear　keys,　six　specimens　with　the　main　variables　were　tested.　Three　failure　modes　of　the　interior　shear　key　specimens　were　observed　during　the　tests.　Moreover,　different　analytical　models　corresponding　to　the　three　failure　modes　and　an　empirical　formula　were　developed　to　estimate　the　seismic　capacity　of　the　specimens.　Compared　with　the　experimental　results,　the　improved　methods　provided　a　more　accurate　prediction　of　the　load-carrying　capacity　than　the　classical　analytical　models.