Abstract: Dark mudstones and the turbidites of deep lake facies were discovered recently in the Member 1 of Yanchang Formation,Upper Triassic in Ordos Basin.Through comparing the measured residual organic carbon,potential hydrocarbon generation amount,kerogen isotopes with the theoretical parameter,it was considered that in this region these dark mudstones are the fairly good or good source rocks.According to the vitrinite reflectance of dispersed organic matter and indexes of maturation of biomarkers the thermal evolution of organic matter in this area is of the characteristics of low-mature or mature.Restudying the source rocks in the Member 1 of Yanchang Formation provides some important message for finding new targets of the exploration of oil and gas in Shaanbei area in Ordos Basin.