Abstract: Based on static loading test analysis, the tensile-compressive fatigue tests of wood in ancient buildings were carried out using the MTS858 machine with a frequency of 2 Hz. The result shows that most specimens failure along the veins of wood. The stress-strain and deformation characteristics of the specimens were analyzed. The stress-strain curves become sparse gradually and the tensile-strain become significant due to the increase of upper stress radio. The deformation growth of the specimen can be divided into three phases similar to the development of fatigue deformation and damage of material, namely, the occurrence of damage, the stable propagation of damage and the failure. S-N relationship of wood sample is plotted with an index function fitted. The upper limit of the stress ratio of ancient wood is suggested to be 0.30.