A sheet pile quaywall with vertical pile anchorage during earthquake is often damaged by lack of resistant capacity of vertical pile anchorage. Authors investigated experimentally vibration characteristics of vertical pile with horizontal load at the top of pile. The pile behavior was analyzed by linear and nonlinear elastic subgrade reaction method. The pile deflection after vibration chould be explanined by reducing coefficient of subgrade reaction. The pile behavior during vibration was analyzed by linear elastic subgrade reaction method in which we took ground deflection into consideration. Some kinds of ground vibration induced excessive stress everywhere in pile.