Quantifying　the　magnitude　of　an　earthquake　is　very　important　for　long-term　and　medium-term　earthquake　prediction,　post-earthquake　emergency　rescue　and　seismic　hazard　assessment.　Paleo-seismology　is　the　investigation　of　past　earthquakes　in　the　geological　record,　in　particular　their　location,　timing　and　size.　Uncertainties　remain　in　the　paleo-earthquake　magnitudes　determined　by　traditional　surface　rupture　parameters,　especially　because　most　seismic　events　do　not　result　in　surface　ruptures　or　are　of　less　than　0.3　m　(M=　similar　to　6-6.8).　To　address　the　problem　of　magnitude　evaluation　of　earthquakes　that　did　not　reveal　major　dislocations,　this　paper　deals　with　the　methods　used　to　determine　the　seismic　shaking　intensity　based　on　the　types　and　forms　of　soft-sediment　deformation　structures,　including　maximum　liquefaction　distance,　thickness　of　disturbed　layer,　empirical　formulae,　and　thickness　of　rapidly　deposited　sand　layer.　Then　we　discuss　and　analyze　these　methods　in　terms　of　their　theoretical　basis,　advantages　and　disadvantages,　accuracy,　applicability　and　problems.　We　chose　two　case　studies:　first,　a　typical　seismics-related　deposit　(liquefied　layer　and　disrupted　layer)　represented　by　a　seismite　in　the　late-Pleistocene　Lake　Lisan　section　near　Masada　in　the　Dead　Sea　Basin;　and　second,　the　liquefied　diapir　triggered　by　an　earthquake　in　the　late-Quaternary　lacustrine　sediments　at　Luobozhai　in　the　upper　reaches　of　the　Minjiang　River,　East　Tibet.　The　five　methods　listed　above　are　employed　to　determine　earthquake　magnitudes　associated　with　the　seismics-related　deposit　and　liquefied　diapir,　yielding　magnitudes　of　5.5-6.5　and　6.0-7.0,　respectively.　The　combination　of　the　five　methods,　provided　a　new　and　relatively　convenient　method　for　determining　seismic　shaking,　especially　in　lacustrine　sediments.　This　study　can　serve　as　a　valid　reference　for　comparing　methods　of　calculating　the　magnitude　of　a　paleo-earthquake　based　on　surface　rupture　parameters,　and　provides　a　better　understanding　of　the　long-term　seismic　activity　and　risk　in　tectonically　active　regions.