In order to match the needs of protection and future repair of ancient architecture, wood structures were studied to identify the wood species in the main hall of Baoguo Temple at Ningbo. Macro- and microscopic characteristics of 287 samples were examined by slice technique and light electron microscopy. The results show that there are nine tree species in the main hall of Baoguo temple, of which six are softwoods, i.e. Cunninghamia, Pinus, Picea, Chamaecyparis, Larix and Glyptostrobus and three hardwoods, i.e. Dipterocarpus, Castanopsis and Castanea.