Abstract: The first member of Shuangyang formation is the main oil layer in L3 well field, Yitong trough. The thickness and distribution of sand bodies have a quick lateral change, with the typical sedimentary characteristic of “close source and short distance”. The characteristics of sand bodies and their oiliness are different between neighbor wells. Therefore, seismic facies analysis technique was used to describe the sedimentary characteristics of sand bodies and their changing rules. The conventional seismic facies parametric analysis technique and Stratimagic seismic facies analysis method were separately used to analyze the seismic facies characteristics of the first member in Shuangyang formation. Then, the results of the two methods were mutually supplemented and verified. On the basis of this, the seismic facies of the first member in Shuangyang formation was classified. The facies marks which can best reflect fan delta and lake facies (such as color of mudstone, lithological combination, sedimentary beddings, sedimentary rhythms and characteristics of logging curves) were adopted to analyze the single well macrofacies from main seismic facies units, on this basis, the corresponding relationship between the seismic facies and sedimentary facies of the first member in Shuangyang formation was established and the seismic facies was converted into sedimentary facies.