Abstract:Late Paleozoic Xishan coalfield in Taiyuan, located at the eastern margin of central Lüliang Mountains, is the production area of coking coal as well as coal bed methane (CBM) in China. Exploration and production show a heterogeneity distribution of CBM and a high proportion of low or free production gas well in the coalfield. Therefore, it should be the basis for predicting the gas enrichment zone to understand the factor that controls the CBM distribution. Because of tectonic uplift against the CBM preservation after the peak period of gas gasgenerating, it is necessary to know the uplift history in order to estimate the key period of CBM preservation. Based on the previous research, we collected five sandstones to perform apatite fission track dating as well as thermal history modelling. The results suggest that sediments in the Xishan Coalfield exited the partial annealing zone since 46±4~52±6Ma. However, basement formation of the core of Lüliang Mountains exited the partial annealing zone in early Cretaceous, which indicates that the edge part uplifted later than the core of the mountains. Xishan coalfield experienced a ‘threestage’ tectonic upliftcooling process during the Cenozoic: i.e., the fast uplifting stage before 48 Ma, the slow uplifting stage between 48±4 and 10±2 Ma, and the intense uplifting stage after 10±2 Ma, which is different from the previous research results. These difference further illustrates the differentiate uplift of Lüliang mountains. The intense uplift (10Ma) coupled with rapid stacking of Jinzhong basin, showing a good basinmountains relationship, and recording the key period for CBM preservation.