1. College of Earth Sciences，Jilin University，Changchun 130061，China; 2. Key Laboratory for Oil Shale and Coexistent Energy Minerals of Jilin Province，Changchun 130061，China; 3. Key- Lab for Evolution of Past Life and Environment in Northeast Asia，Ministry of Education，Changchun 130026，China; 4. Key Laboratory of Mineral Resources Evaluation in Northeast Asia，Ministry of Land and Resources of China， Changchun 130061，China; 5. Daqing Drilling Engineering Company，Daqing 166499，Heilongjiang，China; 6. Shenyang Center of Geological Survey，China Geological Survey，Shenyang 110034，China; 7. Beijing Petroleum Valley Technology Development Co． Ltd． ，Beijing 100085，China; 8． Liaohe Oilfield Branch of Petro China，Panjin 124010，Liaoning，China

According to the analyses on the logging，drilling and geochemical data，the accumulation geolog- ical conditions of Shahejie Formation shale gas in the eastern sag of Liaohe Basin are studied． The rich organic mat- ter mudstone is mainly the dark mudstone deposited on the half deep lake- deep lake and the charcoal mudstone formed from the swamp environment in Shahejie Formation of the eastern sag，which is 3 000 km ² in area． The ma- jor organic carbon values of the dark mudstone range from 1% to 16. 97%，and the kerogen types are mainly Ⅱ 1 and Ⅱ 2 ． The vitrinite reflectance values (Ro) of most organic matter at the low- mature and the high- mature stage． Comparing with five shale gas producing areas in United States， the authors forecast that the Jiazhangsi- Erjie- gou area and the Huangyure area in the eastern sag are rated as the beneficial prospective areas of shale gas accu- mulation． Using the relationship among measuring hydrocarbon gas，porosity and sorbed- gas content to get total gas content，the shale gas resource extent of beneficial prospective areas is 871 ×10 ⁸ m ³ in the third member of Shahe- jie Formation and 742 ×10 ⁸ m ³ in the first and the second member of Shahejie Formation．