This　paper　discusses　numerical　simulation　of　seismic　response　of　underground　structures　in　saturated　soil　deposits.　A　fully　fluid　solid　coupling　model　is　developed　to　simulate　the　dynamic　behavior　of　saturated　soils　during　an　earthquake　and　is　implemented　into　the　commercial　software　ABAQUS　with　a　user-defined　element.　The　model　is　then　applied　to　simulate　seismic　response　of　a　structure　buried　in　a　saturated　soil　deposit.　The　effect　of　burial　depth　on　the　dynamic　response　of　the　underground　structure　is　explored.　The　numerical　simulations　show　that　the　user-defined　element　developed　in　this　paper　is　capable　of　simulating　the　dynamic　response　of　the　underground　structure　in　a　saturated　soil　deposit.　With　the　increase　of　burial　depth,　stress　in　the　underground　structure　is　transferred　from　the　exterior　walls,　top　slab,　and　bottom　slab　of　the　structure　to　its　interior　columns.　The　stress　in　the　deeply　buried　underground　structure　varies　more　significantly　than　that　in　the　shallowly　buried　structure　during　earthquake　excitation.