Abstract: Petrobras discovered three super giant oil and gas fields successively in subsalt sequence of deepwater basins in Santos, Brazil from 2007 to 2008. This paper analyzes the structural evolution and sedimentary filling features, fundamental petrogeologic conditions and subsalt hydrocarbon accumulation features, points out the subsalt series of strata in Campos Basin, Kwanza Basin in transatlantic South Africa and Lower Congo Basin, which are of the same basin in terms of depositional period. They have undergone the same tectonic evolution of passive continental marginal basins. Through analogous research, it is believed that these basins have similar petrogeologic conditions and accumulation features, of which subsalt strata have broad prospect for exploration and they will be important strategic oil/gas strategic zones in the future

Key words: Santos Basin, subsalt series of strata, super giant oil and gas field, Campos Basin, Kwanza Basin, Lower Congo Basin, exploration prospect; strategic oil/gas zone