The　paper　proposes　an　innovative　method　of　analyzing　the　seismic　fragility　of　ancient　timber　architecture.　The　method　is　based　on　the　Copulas,　in　which　correlation　between　different　failure　modes　is　considered.　This　method　is　applied　to　assess　the　vulnerability　of　ancient　timber　architecture　in　Ming　dynasty.　The　assessment　includes　four　steps.　In　the　first　step,　the　incremental　dynamic　analysis　is　employed　to　establish　seismic　vulnerability　curves　of　different　failure　modes　for　the　structure.　After　that,　Copula　joint　distribution　function　is　used　to　analyze　the　correlation　among　different　failure　modes.　In　the　third　step,　fragility　curves　considering　correlation　among　different　failure　modes　are　established.　In　the　last　step,　the　fragility　curves　are　compared　with　those　obtained　by　first-order　bound　method.　The　results　show　that　seismic　vulnerability　of　ancient　timber　architecture　based　on　the　Copulas　is　greater　than　that　of　any　single　failure　modes.　Moreover,　the　occurrence　probability　ranges　between　the　upper　and　lower　boundaries　of　the　first-order　bound　method,　but　is　close　to　the　lower　boundary.