The experiments on the motions for two shallow draft ships have been carried out in regural waves. The results of experiments show that the rolling motion for shallow draft ships change by position of center of gravity of load on deck. In this paper, making use of the Strip Method, the motion characteristics of the shallow draft ship were calculated by computer and personal-computer. Authors proposed simple calculation method of the motion for the shallow draft ship. The results of calculation by the Strip Method and the simple Method were in good agreement with experimental values.