In bridge structures, lateral squeeze due to lateral stress of embankment placement and thermal movement of the bridge structure leads to failure of approach slab, girder, and bridge bearing. Recently, GRS (Geosynthetic-Reinforced Soil) integral bridge has been proposed as a new countermeas-ure. The GRS integral bridge is a combining structure of a GRS retaining wall and an integral abutment bridge. In this study, a series of numerical analysis which considered construction sequences and earth-quake loading conditions were performed to compare behavior of a GRS integral bridge structure and a conventional PSC (Pre-Stressed Concrete) girder bridge. The analysis results show that the GRS integral bridge is more stable than the PSC girder bridge in an aspect of stress concentration and deformation on foundation ground and bridge structures including seismic stability.