Abstract: In China, Qiongdongnan Basin is the only place where large coal type gas fields have been discovered in shallow water, deep water, and ultra-deep water areas. Therefore, it is of important theoretical and practical significance to explore the geological characteristics of natural gas and new exploration fields in the basin. Based on regional geological, seismic, drilling, and geochemical testing, the paper analyzes the accumulation characteristics and exploration potentials of Qiongdongnan Basin. The results indicate that a tectonic framework of "two uplifts and two subbasins" was formed during the deposition period of Yacheng Formation in Qiongdongnan Basin. The coal-type source rocks (including coal-measure source rocks and terrestrial marine source rocks) of Yacheng Formation are the major source rocks, and the source kitchen of coal-type source rocks in the (fan) delta of the Oligocene Yacheng Formation mainly shows a bead-like distribution along the northern margin of the northern depression, the southern and northern margins of the central depression belt. The maturity of coal-type source rocks in the northern margin of the northern depression is low and has not come up to the main gas generation stage. The coal-type source rocks at the southern and northern margins of the central depression belt are mature and have entered the main gas generation stage. Coal-measure source rocks and the surrounding terrestrial marine mudstones developed in each (fan) delta are one source kitchen. As controlled by the source kitchen of the Oligocene coal-type source rocks, two large gas accumulation belts were formed at the southern and northern margins of the central depression belt. The main exploration areas for coal-type natural gas include uplifts, step-fault belts, gentle slope belts, and turbidite bodies inside sags in the gas accumulation belt, showing great exploration prospects, and the natural gas resources are expected to exceed 2×10¹²m³.