As　an　indispensable　part　of　the　Internet　of　Things　(IoT),　wireless　sensor　networks　(WSNs)　need　to　be　completely　integrated　into　the　Internet.　When　an　Internet　user　communicates　with　multiple　sensor　nodes　in　WSNs,　secure　group　key　management　becomes　necessary.　However,　most　current　group　key　management　schemes　developed　for　WSNs　do　not　consider　the　Internet　scenario　while　traditional　group　key　management　in　the　Internet　is　deemed　to　be　not　suitable　for　WSNs　due　to　the　resource　constraint　characteristics　of　WSNs.　In　this　paper,　we　propose　a　group　key　distribution　scheme　for　WSNs　in　the　IoT　scenario　in　which　we　organize　sensor　nodes　into　groups　in　a　hierarchical　structure.　In　the　upper　wired　layer,　an　end-to-end　secure　communication　protocol　is　used　to　distribute　group　keys　for　subgroups　to　the　trusted　head　nodes　and　the　head　nodes　then　distribute　the　group　keys　through　underlying　tree-based　topology　and　wireless　multicast　to　minimize　energy　consumption.　We　also　perform　some　quantitative　analyses　as　well　as　experiments　to　show　that　our　proposed　scheme　is　secure　and　has　t-revocation　capability.　The　total　cost　of　distributing　and　rekeying　the　group　keys　is　also　analyzed　and　compared　to　that　in　some　other　comparable　schemes.