Abstract: In order to study the characteristics of hydrocarbon generating source rocks in different coal measure more objectively, the semi-open system is adopted to carry out the pyrolysis experiment on coal, carbonaceous mudstone and mudstone samples collected from isometamorphic Jurassic coal measure source rocks in Kuqa depression, Tarim basin. The results showed that the gas generating capacity of the isometamorphic coal measure source rocks was good, but there were differences among them. The gas generating capacity of coal and carbonaceous mudstone was better than that of coal measure mudstone. With the increasing of thermal evolution degree, the overall yield (C_1-5) of the coal-measure source rocks increased correspondingly. In the high thermal evolution stage, methane was the main product.The value of carbon isotope pyrolytic gas component of coal measure source rocks was related to pyrolysis temperature. When the pyrolysis temperature increased, methane carbon isotope value reduced first and then increased, while ethane carbon isotope value kept rising. At the same temperature, the δ¹³C₁₌ value of pyrolytic gas was higher than the δ¹³C₂ value.