Abstract: There is lack of profound study on the source rocks in Chang-7 member of Yanchang formation in the central and western Ordos basin, which restricts the oil and gas exploration process in the area. In order to clarify hydrocarbon generation conditions of the source rocks in Chang-7 member, the paper makes a systematic analysis on distribution and geochemical characteristics of Chang-7 source rocks in the area based on enormous amounts of actual data and previous research results, predicts favorable areas for oil and gas exploration and provides basis for tight oil exploration in Yanchang formation in the study area. The results show that the depocenters of the source rocks in the study area were mainly located in Jiyuan, Gengwan, Eastern Huan County, Baibo and Zhifang area during the deposition of Chang-7 member. The dark shales with large average cumulative thickness in Chang-7 member are characterized by good organic matter type, high organic matter abundance and high thermal evolution degree (indicating a stage of hydrocarbon generation), which belong to typical high-quality lacustrine source rocks and are major source rocks of Yanchang formation in the area. 6 favorable exploration areas are determined in the study area, including the western Youfangzhuang area to the south of Dingbian, the area to the east of Jiyuan, the area to the south of Tiebiancheng, northeastern Tiebiancheng area, northeastern Huan county and the area to the south of Baibo