It is well known that ship platings near the bow suffer some damages caused by the water impact pressure. In order to investigate this phenomenon, it is necessary to analyze the nonlinear dynamic response of ship platings. This paper presents the methods for calculating the response of ship platings. At first, the authors study the applicaton of the Mode Superposition Method to dynamic response problems which are analyzed by F. E. M., and obtain a formula of direct numerical integration based on the calculus of variation and show its usefulness. Then, based on the abovementioned results, the authors study a simplified method to estimate the maximum response approximately, using a linear system of a single degree of freedom equivalent to ship plating. The results obtained are as follows : (1) The Mode Superposition Method presented here is useful for estimating the dynamic response of ship platings from a viewpoint of time and accuracy in computation (2) The formula of numerical integration obtained in this paper is considered to be equivalent to Newmark's β method when β=1/6, and takes as much time in computation as β method. (3) The simplified method of estimating the maximum response has good accuracy for practical use.