In　order　to　protect　Chinese　ancient　buildings,　seismic　characters　of　tenon-mortise　joints　of　Chinese　ancient　wooden　construction　are　studied　by　numerical　methods.　Model　of　an　one-storey　wooden　construction　is　built　which　considers　3　types　of　connection　joints　of　beam　and　column:　Swivel　joint,　rigid　joint　and　semi-rigid　joint　(tenon-mortise　joint).　Motion　Equation　of　the　model　under　seismic　force　is　deduced　and　modal　as　well　as　time-history　analysis　are　carried　out　to　study　dynamic　characters　and　earthquake　responses　of　tenon-mortise　joints.　Different　column　base　conditions　are　also　considered　for　earthquake　response　analysis.　Results　show　that　compared　to　the　other　two　types　of　joints,　basic　frequency　of　the　model　with　tenon-mortise　joints　is　smaller,　under　earthquake　forces　its　peak　values　of　acceleration　are　lower　which　shows　its　good　aseismic　characters.