The Carboniferous-Permian lithologic association of Xiangtan 9 well in Ejin Banner is composed of volcanic rocks and clastic rocks, the concordia ages of volcanic zircon are from (302.2a±7.8) Ma to (319.9a±4.5) Ma, which shows that the stratigraphic age is late Carboniferous. The results of geochemical characteristics of some drill hole cores indicate that the organic matter abundance is middle-higher, the kerogen type is Ⅰ—Ⅱ1, and the organic matter has developed into the mature-high mature period. The kerogen type evaluation shows that H/C-O/C of the core samples can better reflect kerogen type, but the kerogen type is not effectively evaluated by H/C-O/C of the surface samples due to the decrease of H resulting from the weathering effect.oft-com:office:office" />