Abstract: Hydrocarbon source rock prediction and evaluation cannot be carried out in low exploration degree areas with fewer drilled wells,limited core data and lacking of analysis data.This study tried to use geophysical methods to predict and evaluate the hydrocarbon source rocks in Hari sag of Yingen-Ejinaqi Basin.The application results indicate after comparing between predicted effective hydrocarbon source rock thickness by using geophysical method and drilling result of Yingen formation and Suhongtu formation for well HC1,the relative error are only 6.4% and 5.6% respectively.This comparison result proved that the prediction method is practicable and result is reliable.According to the geological situation of Hari sag,the previous logging calculation model of the TOC of hydrocarbon source rock was revised,the coincidence of TOC value was high between the calculated result and measured result,which proved that the formula and the calculation method is suitable and correct.This study shows by using geophysical method to predict and quantitative evaluate the hydrocarbon source rock is quite feasible and effective.