In order to enhance accuracy of hydrocarbon reservoir prediction in shallow water lacustrine deltaic depositional system, we put forward a new and more comprehensive depositional model based on the deposits of the Ganjiang River Delta in Poyang Lake. Using cores, sketch logs, trenches and laboratory analyses, we described these deposits. Several basic attributes have been recognized for shallow water delta, including: (1) The sand body is comprised of architectural elements including channel bars and levee in both of upper and lower delta plains, and longitude bars, transverse bars in river moth areas, especially unit bars in bar head areas. (2) Normal grading is absent in channel fill sediment in straight channel reach. (3) Facies sequence of floodplain sediment is mainly composed of interbedded mudsand deposited in flood stage on top, typical with lacustrine mud overlain by reverse-grading upward distributary mouth bars at lower part. (4) The delta formation process is mainly influenced by the climate cycles or flooding events. At low-flow stages mud is deposited in delta front. At high stages, older sediment is reworked, and the interbedded sand-mud is deposited in delta plain. This depositional model quality represents the evolution process of shallow water lacustrine delta, and it would help to identify reservoir sweet spot in subsurface extensive sand body of these kinds of depositional systems.