To　protect　Chinese　ancient　wooden　buildings,　by　simulation　means　a　decayed　wooden　beam　of　an　ancient　building　in　the　Forbidden　City　was　taken　as　example　to　study　its　bearing　performances　after　strengthened　by　steel　bands　and　bolts.　The　ancient　wooden　beam　was　found　to　decay　on　its　forepart.　The　decayed　part　of　beam　was　considered　to　be　replaced　by　new　wooden　part,　which　connected　with　old　part　of　beam　by　bolts　and　steel　bands.　Finite　element　model　of　the　strengthened　beam　was　built　considering　swivel　type　of　boundary　conditions.　By　contact　analysis　of　ANSYS　program,　distortion　value,　compression,　tension　as　well　as　contact　stresses　of　the　strengthened　beam　under　vertical　loads　were　obtained,　feasible　strengthening　suggestions　were　proposed.　Results　show　that　inner　forces　and　distortion　value　of　the　strengthened　beam　are　within　permission　scopes,　thus　the　strengthening　method　is　feasible.　©　(2012)　Trans　Tech　Publications,　Switzerland.