Abstract: Taking the nearshore subaqueous fan of the third member and the forth member of the Shahejie formation in the eastern of the northern steep slope zone in Dongying depression for an exampale, the quantitative functional relationship between the physical properties cutoff values of the effective reservoir and the buried depth was obtained by several methods, and then the porosity evolution followed the buried depth and its control action to hydrocarbon accumulation in different subfacies of the nearshore subqueous fan are studied. For the nearshore subqueous fan buried above 3200m, all the inner fan，middle-fan and outer fan can develop effective reservoirs, and the “self-generating and self-reserving” or “generating in older formation but reserving in younger formation” structural reservoir and the structural-lithologic reservoirs are main reservoir types. For the nearshore subqueous fan buried below 3200m, the physical properties of the inner fan are lower than the cutoff, so there were no effective reservoirs developed; the sand-conglomerate of the middle-fan developed more effective reservoirs. Because of the change of the physical properties of inner fan and middle-fan, the nearshore subqueous fan buried below 3200m has the reservoir forming feature of “outer fan migration, middle-fan accumulation, inner fan sealing”, and the middle-fan formed the “self-generating and self-reserving” lithologic reservoirs, which depend on the lateral sealing of the inner fan and the sealing from the lacustrine mudstone.