In order to study the influence of tower stiffness on suspension bridge, this paper took Xihoumen Suspension Bridge as a prototype, established its finite element model by using BNLAS (Bridge Nonlinear Analysis System), which was developed by Southwest Jiaotong University. This model is a two-mtower single-mspan suspension bridge with the main cable span of 1 650 m, and it has single-mspan simply supported girder. Then, the influence of suspension bridge structural performance with different tower stiffness was analyzed by changing the model's tower stiffness (0.7, 0.8, 0.9, 1.0, 1.1, 1.2 and 1.3 times of original tower stiffness). This paper also discussed the influence of mid-mtower stiffness in multi-mtower and multi-mspan suspension bridge.