There are potential for tight oil in the Shahejie Formation in Bohai Sea area. Geological characteristics and forming conditions of tight oil were researched in the Shahejie Formation in northeastern subsag of Laizhou Bay Sag，which is based on the well drilling，well logging，geological log and seismic data and combined with the core observation，thin section analysis and a lot of laboratory analysis data about geochemical and reservoir physical property. The research results show that there are geological conditions for tight oil in northeastern subsag of Laizhou Bay Sag，where oil and gas mainly accumulate in the widespread effective reservoirs that are interbedded or contacted with high-quality hydrocarbon source rocks. Dark gray mudstone，deposited in semi-deep and deep lacustrine facies withⅡ1 type kerogen，distributes widely in the third member of Shahejie Formation，which provides sufficient oil source supply for tight oil formation. Large-scale rapidly deposited delta sand bodies in the Shahejie Formation provide storage space for tight oil accumulation. Alternativelydeposited layers of high-quality hydrocarbon source rocks and large thick good reservoir result in a good relationship between source and reservoir，which provides benefit configuration conditions for near-source hydrocarbon accumulation. Abnormal pressure provides driving force for charging during the hydrocarbon accumulation period for tight oil formation.