This article studies the quantity,grain size,and distribution characteristics of the deltaic sedimentary,also sedimentary structure and construction of the delta.The following conclusions are obtained.(1) In every subdeltaic construction,the thickness,velocity and land sedimentary ration are in relation to their living time and abandoned pattern.There is a maximum in every subdeltaic sedimentary.(2) The coarsest grained-grad is 0.25mm,and principal composition is salt sand and clay.There is nonrolling components of sedimentary.(3) The sedimentary structures are in relation to the hydrodynamics and grain size of sediments.The distribution and construction of the deltaic sedimentary is a reflection of the characters of the deltaic development.