Abstract: It is important to underst and the damage state of Yingxian wooden tower for its overhaul and repair. The weakened performance of the wood elements,the actions of strong external forces, the effects of the environmental change and the factors of the unfavorable human-activities have continuously accelerated the damage of the tower. In this paper, the physical and mechanical performances of the old wood material are obtained. The types, the intrinsic mechanisms and external factors of the damage of the tower are systematically analyzed. New analytical methods are proposed specifically for ancient building structures, which form the bases of repairing method developed for Yingxian Wooden Tower. It is pointed out that there is possibility for the second and third stories of the tower to collapse under 8 degree earthquake and serious damage under 7 degree earthquake. After analyzing the historic repair characters of the tower, new repair methods are proposed.