Studies of depression structure-styles show there are variant typical depressions in Yingen-ejina rift group basins, which are single-fault depression and double-fault depression. The single-fault depressions may classify in detail asthe following: single fault bench type; single fault trough type and single fault overlap type etc. The double-fault depression mainly be double fault graben type. According the relationship of Jurassic and Cretaceous structural layers, these depressions may be classified into two types: single fault overriding depression and single fault migration depression. Hydrocarbon source rocks in different structure-style type of depressions have variant states of distribution and conservation. Distribution of source rock is mainly controlled by sub-trough of  each depocenter. Source rock in succeed depression is in good condition and well   disposed with local structural traps in stage faults zone and overlap sandstone bodies of plain slope. The source rock in migration depression is eroded in some degree, but the source rock of middle-lower Jurassic is well deposed with the stratigraphic non- conformity traps. So, the overlap zone in plain slope of single-fault depression is prospecting in stratigraphic traps exploration and stage fault bench zone in plain slope is favorable in structural traps.