To　improve　accuracy　of　safety　state　evaluation　results　for　ancient　timber　buildings　and　to　know　the　real　state　of　the　building,　a　safety　grade　evaluation　model　of　ancient　timber　buildings　is　established　based　on　attribute　mathematic　theory.　From　the　perspective　of　macro,　micro,　qualitative,　and　quantitative,　22　factors　may　adversely　affect　the　safety　state　of　ancient　timber　building　are　considered　in　this　model.　First,　evaluation　system　is　established,　and　evaluation　indexes　are　selected　based　on　former　study,　seismic　damage　data,　and　Chinese　current　code　about　ancient　timber　buildings.　In　the　evaluation　system,　whole　building　is　divided　into　four　parts,　which　are　wood　frame,　enclosing　wall,　foundation,　and　plinth.　Different　parts　contain　different　components.　Every　component　has　its　own　evaluation　indexes.　Second,　based　on　the　AHP　and　entropy　method,　the　comprehensive　empowering　method　is　used　to　determine　the　weights　of　the　indexes.　Third,　the　attribute　recognition　model　is　established　to　identify　the　safety　grade　of　components　or　units.　Fourth,　based　on　the　evaluation　results　of　components,　safety　grade　of　units　is　identified.　Then,　safety　degree　of　the　entire　building　is　determined　by　the　minimum　safety　grade　of　units.　At　last,　the　model　is　applied　to　the　Liben　hall　in　village　Siping,　Zhejiang　province,　China,　and　the　assessment　results　are　consistent　with　the　results　of　damage　identification.