Considering the structure of pile supported wharf,the response spectrum method was used to analyze the seismic response under different horizontal earthquake directions in a foreign wharf engineering project.The change rule of the structure displacement and internal force of pile foundations under the influence of different direction of earthquake is compared and studied.The results show that horizontal torsion effect has a significant influence on structure and the seismic effect of wharf structure should be calculated by translation-torsion coupling mode-superposition method while the center of mass and rigidity are inconsistent.In the condition of horizontal direction earthquake effect,the horizontal seismic force of pile closed to the landside is the biggest while the horizontal seismic force of side pile is bigger than that of middle pile group.The force influence of corner pile must be check and taken in account and the pile arrangement shall be adjusted to reduce the adverse effect caused by structure torsion during design project.