Abstract: Located in the Northeast Indian Ocean,the deep water basin of the Bay of Bengal is one of the most potential petroliferous basins in Asia-Pacific Region. Based on previous studies and the data of DSDP sites 217 and 218, this article deals with the petroleum geological characteristics of the deep water basin. The results show that (1) the strata of the basin can be divided into 3 seismic sequences, and two stages of sedimentation, the Bengal fan and pre-Bengal fan. (2) The tectonic evolution of the basin has close relation with the separation of Indian plate from Gondwana. (3) Even though the organic matter is low in the deep water basin, it has entered into the a mature stage. (4) Braided channel sandstone in the Bengal fan could be good reservoir bodies. In conclusion, there are possibilities to find lithologic oil and gas reservoirs in the Middle-fan of Bengal.