In　order　to　study　the　seismic　response　of　underground　structures　when　liquefied　soil　layer　is　located　in　different　positions,　the　PL-Fin　constitutive　model　proposed　and　developed　in　FLAC3D　was　used　in　this　paper.　The　time　when　large　deformation　occurred,　liquefied　area　distribution,　the　law　and　difference　of　pore　water　pressure　and　excess　pore　water　pressure　ratio,　the　law　of　the　displacement　characteristics,　and　differential　settlement　of　structure　were　summarized.　Their　differences　were　also　compared　and　analyzed　when　the　structure　is　on　non-liquefied　soil　layer.　The　primary　conclusions　are　as　follows:　the　displacement　of　structure　was　the　largest　when　liquefied　soil　layer　was　under　structure　and　caused　the　structure　sink;　the　liquefied　soil　on　both　sides　of　the　structure　caused　the　structure　float　upward,　and　increased　the　displacement　between　the　layers　of　side　walls　in　the　horizontal　direction　as　well　as　between　the　roofs　and　floors　in　the　vertical　direction;　the　soil　displacement　and　the　displacement　and　differential　settlement　of　structure　were　all　not　the　largest　when　structure　was　all　located　over　the　liquefied　soil,　so　it　was　not　enough　to　only　study　the　law　when　structure　was　embedded　in　liquefied　soil;　the　law　of　the　y-displacement　of　story　drift　on　top　plate　was　similar　when　the　liquefied　soil　was　located　at　six　different　positions　including　around　the　structure,　on　its　two　sides,　in　its　bottom,　in　45　degrees　at　the　bottom　of　the　location,　on　its　two　sides　and　45　degrees　at　the　bottom　of　the　location,　and　in　its　bottom　and　45　degrees　at　the　bottom　of　the　location,　but　the　response　of　liquefied　soil　and　the　influence　on　the　structure　performance　were　different;　and　the　large　deformation　caused　by　liquefaction　occurred　in　1　to　3　seconds　after　the　jump　of　pore　water　pressure　and　the　excess　pore　water　pressure　ratio,　so　their　mutation　can　be　considered　as　judgement　on　whether　the　large　deformation　occurred　or　not.　©　2017,　Editorial　Department　of　Journal　of　Hunan　University.　All　right　reserved.