Aiming at the fact that all-vertical-piled wharf is prone to rotation than ranking-piled-wharf under the action of lateral force,we analyze the calculation method of rotation stiffness of all-vertical-piled wharf,and obtain a formula which based on rotation stiffness is derived to calculate the distribution of lateral force on all-vertical-piled wharf.Combining with an engineering example,we calculate the rotation stiffness and lateral force distribution coefficient of the wharf by the proposed formula in three different conditions of the width and length ratio.The results show that the increase of the width and length ratio will increase the rotation stiffness of the wharf,and make the lateral force distribution coefficient on each bent more uniform.The results obtained by the proposed formula agree well with the results by FEM(finite element method).As the rotational stiffness of the wharf increases,the difference between the calculated value of the formula and the norm value increases,and the maximum difference of the maximum horizontal forces distribution coefficient is 22%.