The Fuyu Layer of Cretaceous Quantou Formation in northern Songliao Basin developed a set of low permeable tight sandstone reservoirs formed in river to shallow-water delta environments. Proven reserves in the Fuyu Layer was preserved in reservoir rocks with average porosity of 11. 8％ and average permeability of 2. 30×10^-3 μm², lithology reservoir was the main reservoir type. The remaining exploration targets of the Fuyu Layer were tight reservoir with porosity less than 10％ and permeability less than 1×10^-3 μm² . The main controlling factors of the tight oil accumulations in Fuyu Layer could be listed as follows: The mature source rocks controlled the distribution range of tight oil;the structural heights were the target areas for petroleum migration and accumulation;the NW fault belts controlled the petroleum enrichment areas; the channel sand bodies controlled the tight oil “sweet spots”. Based on the analogy method, the exploration potential for tight oil accumulations in Fuyu Layer was evaluated, and the preliminary result is about 13. 09×10⁸ t tight oil to be proved, which would provide an important resource support for Daqing Oilfield.