Abstract: The present research and exploration conducted in East China Sea Shelf Basin indicate that the Mesozoic has exploration potentials. Based on 2D seismic data acquired in recently and regional geological data, theauthor made a preliminary evaluation the formation, hydrocarbon source condition, reservoir-cap condition and petroleum system in the Mesozoic of the Southern East China Sea Shelf Basin. The results indicate that Mesozoic strata are widely distributed and well developed, with Marine hydrocarbon source rocks in the Lower and Middle Jurassic, as well as the transgression lacustrine hydrocarbon source rocks in Lower Cretaceous. Mesozoic basin of this area has potential for hydrocarbon exploration.