The geologic condition of petroleum accumulation is analysed, petroleum dispersion regularity is discussed and the target of petroleum exploration of the Taibei depression of the Tuha Basin in Jurassic is provided. In Jurassic of the TaiBei depression of the Tuha Basin, the foundamental geologic conditions for petroleum accumulation consist of four good source beds which are divided into two types. Numerous sand bodies that have good reservior function, effective traps, two regional covers which can enclose perfectly and excellent disposition condition of the source, reservior and cover. The structure trap and structure-lithologic trap are main types of the oil and gas accumulation. Encircling main source depression and the sand body along short axis distribution and the ancient structure of Yanshan cycle and the pile up structure of Xishan cycle are principles of oil and gas accumulation. Varied activity source faults control oil and gas distribution. The middle part of the depression, foremountain fault-fold bets, Huoyan mountain anticline belt and the upper/down side of the overthrust fault are our exploration targets in the future.