Distributing　real-time　video　stream　in　large　scale　group　communication　over　Internet　poses　several　challenging　problems　due　to　the　complex　network　dynamics,　stringent　requirement　of　delay　and　loss.　This　paper　proposes　a　novel　peer-to-peer　scheme,　named　TeamCast,　to　combat　with　these　issues.　Constructing　multiple　diverse　application　layer　multicast　(ALM)　trees　to　transmit　multiple　independent　complementary　descriptions　produced　by　multiple　description　coding　(MDC)　simultaneously,　TeamCast　improves　error　resilient　ability　in　the　presence　of　various　levels　of　packet　loss　caused　by　unpredictable　congestion　of　Internet　and　node　failure,　as　well　as　enlarges　system　capacity.　The　results　of　extensive　simulations　indicate　that　TeamCast　achieves　low　latency,　scalability,　and　fault　tolerance　for　the　delivery　of　live　media　stream.