Based on the latest seismic and drilling data, the formation conditions of gas reservoir and the controlling factors of gas accumulation of the Rovuma Basin in East Africa have been analyzed. The results show that the Rovuma Basin has excellent conditions for hydrocarbon accumulation. In the study area, the source rock is mud shale of Permian-Triassic, Jurassic and Cretaceous which developed in the rift period, and the reservoir is the Paleogene turbidite sand, and the regional caprock has several sets of the marine mudstone widely distributed in Paleogene. It is concluded that the tectonic activities controlled the oil and gas accumulation in this area, and good caprock conditions are the key factor for hydrocarbon accumulation and preservation. It is pointed out that the relatively stable area, especially the continental slope area with weak tectonic deformation during the latest extensional deformation is a priority exploration region, and the optimal selection of exploration block should avoid the area with large scale faults that extend to sea floor, and the regional caprock conditions should be evaluated emphatically.