Seismic　groundwater　level　anomalies　caused　by　earthquakes　are　characterized　by　diversity　and　complexity.　To　further　explore　the　mechanism　between　deep　groundwater　dynamics　and　seismic　activity　and　to　play　an　indicative　role　of　groundwater-level　to　seismic　activity,　taking　2008　Wenchuan　Ms8.0　earthquake　and　2007　Sumatra　earthquake　Ms8.5　as　case　study,　by　the　analysis　of　groundwater-level　in　the　regions　including　Sichuan,　Yunnan,　Gansu,　Shaanxi,　Chongqing,　the　study　summed　up　the　different　response　characteristics　and　regularity　of　the　same　well　water　level　to　the　two　earthquakes.　Groundwater　level　response　characteristics　to　distant　earthquake　mainly　appeared　oscillation-type　and　step-type,　the　occurrence　of　anomalies　was　later　than　the　earthquake.　Groundwater-level　response　characteristics　to　local　earthquake　was　relatively　complicated,　mainly　appearing　step,　pulse　and　oscillation　types,　and　the　occurrence　of　anomalies　was　as　almost　simultaneous　with　earthquake.　And　according　to　the　response　mechanism　of　groundwater-level　to　crustal　stress,　the　authors　analyzed　the　different　response　reasons　of　typical　well　water　levels　to　distant　and　local　earthquakes.　The　groundwater-level　response　to　distant　earthquake　is　due　to　the　seismic　wave　stress　on　the　aquifer　medium.　The　groundwater-level　response　to　local　earthquake　is　mainly　due　to　the　regional　tectonic　stress　and　the　seismic　wave　stress　on　the　aquifer　medium.　The　smaller　the　epicenter　distance　is,　the　greater　the　seismic　tectonic　stress　field　under　the　aquifers　is.