During the Iwate-Miyagi Nairiku Earthquake in 2008, intensive seismic motion and some special behavior of the dam body were recorded at Aratozawa Dam, a 74.4 m high rockfill dam of 15 km from the epicenter. For investigating the mechanism of the abnormal behavior of the dam, several numerical analyses have been performed in Japan and France with different methods. In this paper, 3 kinds of different methods, i.e. the equivalent linear analysis, the nonlinear full stress analysis and the effective stress analysis are compared. The features of the analysis methods, the conditions and results are described. Finally, based on the comparison, some suggestions are given on selecting the analysis methods and setting of the analysis conditions.