Human　enterovirus　71　(EV71)　is　one　of　the　major　causes　of　hand,　foot　and　mouth　disease　(HFMD),　which　leads　to　significant　mortality　in　infected　children.　A　prophylactic　vaccine　is　urgently　needed.　However,　little　is　known　about　the　protective　T-cell　immunity　in　individuals　infected　with　the　EV71　virus.　In　this　study,　we　performed　a　comprehensive　ex　vivo　interferon-gamma　ELISPOT　analysis　in　31　children　infected　with　EV71　as　well　as　in　40　healthy　adult　controls　of　the　CD4(+)　and　CD8(+)　T-cell　responses　to　overlapping　peptides　spanning　the　VP1　structural　protein　and　RNA-dependent　RNA　polymerase　(RdRp)　non-structural　protein.　EV71-specific　CD4　T-cell　responses　were　detected　in　most　of　the　acute　patients　and　were　mostly　CD4-dependent　RdRp-specific　responses.　CD8-dependent　VP1　and　RdRp-specific　responses　were　also　detected　in　a　small　proportion　of　recently　infected　children.　There　was　no　significant　association　between　the　strength　of　the　T-cell　responses　and　disease　severity　observed　during　the　acute　EV71　infection　phase.　Interestingly,　an　RdRp-specific,　but　no　VP1-specific,　CD4-dependent　T-cell　response　was　detected　in　30%　of　the　adult　controls,　and　no　T-cell　responses　were　detected　in　healthy　children.　In　addition,　24　individual　peptides　containing　potential　T-cell　epitope　regions　were　identified.　The　data　suggest　that　CD4-dependent　RdRp-specific　T-cell　responses　may　play　an　important　role　in　protective　immunity,　and　the　epitopes　identified　in　this　study　should　provide　valuable　information　for　future　therapeutic　and　prophylactic　vaccine　design　as　well　as　basic　research.