Abstract: Coastal sedimentary basins in West Africa are originally formed on a typical passive continental margin. Most of them are rich in petroleum resources. The El Aaiun Basin is located in the southern Morocco, of which the tectonic position is different from others in West Africa. In the beginning, the El Aaiun Basin was not only controlled by the movement of African and South American plates, but also North American plate. In the later stage, it was influenced by the Atlas Saharien orogeny. Since the Pan-African orogeny, however, the El Aaiun Basin has remained stable in tectonics, in spite of local volcanic activities. There filled with huge detrital and carbonate rocks as well as halite formations in the basin. Source rocks of hydrocarbon and reservoirs are widely developed. It seems that there are uncertainties in petroleum exploration in the basin for the time being, it remain as an attractive target for oil explorations as long as the studies aiming at source, reservoir and cap rocks are accelerated. Moreover, the use of advanced technology for deep-sea exploration will certainly help the exploration in the basin.