Abstract: Based on the character of source rocks of the oil pools at Banqiao and Qikou in the central part of Huanghua depression, the process of evolution of organic matter into hydrocarbons is divided into four stages, with the thermal window for oil formation at 85.5-163℃(2,000-4,200 meters). According to the properties of alkanes, source rocks of Paleogene of this area are classified into 5 types and crude oils into 2 main groups in 6 subdivisions. Oil sources are compared on the same basis, which leads to the supposition that the condensates in the pool at Banqiao come from the source rock in No. 3 shahejie Section, while the oil in the pool at Dagang-Tangjiahe has its source in No. 2 and No. 3 Sbahejie sections.