The Sanghe sub-sag in Baiyinchagan sag develops three sets of source rocks, i.e. the first Member of Duhongmu Formation, Tenggeer Formation and the second Member of Aershan Formation. The three sets of source rocks are the important oil sources in Sanghe region. The analytical data show that crude oil in the region can be divided into three types, primary low mature crude oil, primary mature crude oil, and blend crude oil. The first two types of which come from lower Member of Tenggeer Formation and the second Member of Aershan Formation, they are the hydrocarbon products in different periods of source rocks. The third type of crude oil, typical binary blend crude oil,  comes from the mixing process of the first two types.