Huhehu Sag is the new area of oil and gas exploration in Hailar Basin in future.Its exploration is low degree and the research of source rocks is weakness.Elaborate evaluation of source rocks has an important significance to the forecast of favorable zone.This paper is based on the basic principle of sequence stratigraphy and geochemical and comprehensive applies these information including the total organic carbon,hydrocarbon generating potential,chloroform bitumen \"A\",element characteristic of Kerogen, Pyrolysis Characteristic of rocks, Kerogen types index,maceral characteristic,vitrinite reflectance and steroid terpane characteristic.The characteristic of source rocks of different sequence and different system tracts in one sequence is studied and evaluated. Results of this research show that the heterospheric characteristic of source rocks is obvious.The layer of hydrocarbon generating mainly lies in the TST and HST of Sq4、Sq3 and Sq2.The source rocks of the TST of Sq3 and Sq2 is the best.Applying this method to evaluate source rocks has very important significance for exploration both Huhehu Sag and other basins which are low exploration degree and few drilling wells.