Ancient Chinese timber structures include mainly post and lintel and column and tie construction systems, the structural arrangement and connection joints of which are obviously different from those of modern timber structures. In order to improve the engineering practicability of structural calculations and the structural safety assessment of ancient Chinese timber buildings, simplified calculation methods were advanced. The mechanical performances of common timber rafters, common timber purlins, three-purlin beams and five-purlin beams were studied. In addition, based on the analysis of dynamic characteristics of some typical timber structures, approximate calculation models for the basic structural natural periods of these typical timber structures were proposed. These results may provide a basis and reference for structural calculations, structural safety assessments and strengthening designs of ancient Chinese timber structures.