Abstract: The studies of organic abundance, type and maturity of source rocks from wells in the eastern Tarim Basin showed that the Middle-Lower Cambrian source rocks were the most favorable source rocks in the study area. The organic abundance was high, with the average TOC content higher than 1.0%. The organic type was good, generally type Ⅰ-Ⅱ₁. The organic maturity was high, with Ro ranging from 0.88% to 2.75%, indicating for high-mature and over-mature stages.