Drill　sample　data　for　the　actual　project　level　evaluation　of　sand　liquefaction　evaluation　is　limited　and　different　objects　falling　into　the　same　level　interval　lead　level　is　difficult　to　distinguish　the　evaluation　object,　the　establishment　of　a　sand　liquefaction　grade　evaluation　model　based　on　the　principle　of　information　diffusion.　Firstly,　select　the　earthquake　magnitude,　ground　acceleration,　SPT　cardinality,　soil　clay　content,　effective　stress　to　build　sand　seismic　liquefaction　evaluation　system.　Secondly,　the　use　of　information　diffusion　theory　into　multiple　discrete　indicators　will　determine　the　point,　the　diffusion　of　information　of　each　evaluation　to　a　single　value　for　each　discrete　point,　in　order　to　build　sand　liquefaction　grade　fuzzy　evaluation　information　diffusion　matrix.　Finally,　an　example　analysis　shows:　sand　liquefaction　evaluation　results　and　actual　discrimination　cases　coincide　sand　liquefaction　prevention　able　to　provide　theoretical　support.　©　2014,　EJGE.