Two dimensional FEM dynamic analysis with joint element was conducted to investigatethe mechanism of damage to caisson-type quaywall in Kobe port caused by 1995 Hyogo-Ken Nanbu Earthquake. In this analysis, excess pore water pressure in the replacement sand and backfill is not taken into account. According to the results, analytical residual displacement of caisson is smaller than the actual one. If present method is an appropriate one, we can conclude that excess pore water pressure played an important part in the actual damage to caisson -type quaywall. However, present method is not verified enough for large-deformation problems. This verification should be caried out through comparison with model tests, etc.