Abstract: The Zengmu basin lies in the Sunda shelf. A great number of sediments brought in by the ancient Sunda River and features of Zengmu basin shelf may have made shelf-margin deltas develop in the south of the basin,and such shelf-margin deltas in the south of the Zengmu basin have also been proved through the analysis of drilling core and seismic characteristics. The sedimentary bodies in the shelf-margin deltas of the basin occur as wedges thinning towards land and sea.The sediments brought by the Sunda River formed many sets of sedimentary complexes. These sedimentary bodies have good oil and gas prospects because of good source-reservoir conditions of them.