Abstract: The Wenchang and Enping Formations are the two effective source rocks in the Huizhou sag of Pearl River mouth basin, which has been confirmed an oil and gas bearing sag. The deep lacustrine source rock in the Wenchang Formation has always selected as the exploration target. With the development of oil and gas exploration, the contribution of shallow lacustrine-swamp facies source rock represented by Enping Formation in Huizhou area becomes increasingly attractive. It is proved that the hydrocarbons produced from the new region of the eastern Huizhou sag comes mainly from the shallow lacustrine-swamp facies source rocks. This article is devoted to the source rocks of shallow lacustrine-swamp facies in the Huidong area. A summary of the characteristics of the new source rocks and the new area are presented and described in this paper. It suggests that the existence of multiple hydrocarbon source rocks in the sag will certainly promote the exploration process in the area.