Abstract: Modern geochemical analysis and biomarker analysis methods, the characteristics of Chang 7 Member and Chang 9 Member source rocks in Zaoyuan exploration area of Ordos basin were studied, and oil source correlation of Chang 4+5 Member Chang 61 Member and Chang 8 Member crude oil samples were carried out. The results show that the organic matter abundance of the source rocks of Chang 7 Member in the study area is higher, the type of organic matter is Ⅱ1-Ⅱ2, and the configuration of regular sterane C27-C28-C29 is V-shaped or partially V-shaped, which is the characteristic of sapropel; The organic matter abundance of Chang 9 Member source rocks is lower, the type of organic matter is Ⅱ2, and the configuration of regular sterane C27-C28-C29 is L-shaped, which is the characteristic of close mixing with terrestrial higher plants. The results show that the crude oil Pr/Ph ratios of Chang 4+5 Member, Chang 61 Member and Chang 8 Member are between 0.78 and 0.85, which indicate that their sedimentary environment belongs to a freshwater reducing environment; The crude oil of Chang 4+5 Member, Chang 61 Member and Chang 8 Member come from the same set of continental freshwater lake source rocks similar to Chang 61 Member, belonging to medium low mature crude oil. The crude oil of Chang 8 Member is more mature than that of Chang 4+5 Member and Chang 61 Member. The crude oil of Chang 4+5 Member, Chang 6 Member and Chang 8 Member in Zaoyuan exploration area is mainly from the dark mudstones, the main contributor is the Zhangjiatan shale of Chang 7 Member, and the dark mudstone of Chang 9 Member also makes a small contribution. 

Key words: source rock evaluation')">

source rock evaluation, oil source correlation, geochemistry, Zaoyuan exploration area, Yanchang Formation, Ordos basin