Abstract: China has abundant weathered coal resource,but it has limited application because of its highly oxidized u- nique properties. At present,it is mainly used to improve soil properties and produce humic acid. Biomethane produc- tion with weathered coal as substrate is an exploratory new bio-fermentation process,exploring its feasibility and the change of physical characteristics of weathered coal in the process of simulation experiment is conducive to broadening the utilization of weathered coal resource and improving the environment,and can further enrich the theory of biogas production from coal. Coal samples with different weathering degrees from Wuhai in Inner Mongolia and Jincheng in Shanxi were selected for the experiment. Using coal mine water as the source of microbial community,the simulated gas production experiments were carried out under suitable environmental conditions,and the biogas production capacity and internal factors of coal with different weathering degrees were analyzed through biogas simulation and infrared spectroscopy test,to reveal its gas production potential and physical characteristics. The study results show that ① with the deepening of weathering degree of coal,the gas production of com-bustible CH4 was increased. The highest produc- tion of combustible CH4 in two groups of coal samples reached 7. 13 mL / g and 4. 20 mL / g respectively. ② Coal sam- ples with different weathering degrees had gas production peaks and the time basically appeared between 15 and 30 days. The peak of gas production was getting earlier and earlier with the deepening of weathering degree of coal sam- ples in each group. ③ With the increase of weathering degree of coal, the aromatic ring in coal was continuously opened and the macromolecular structure was destroyed. At the same time,the content of hydroxyl and amino groups in coal tended to decrease,the structure of lipid-carbon was disintegrated,and the oxygen-containing functional groups became the main structure,the proportion of oxygen content increased continuously,which made it easier to degrade for microorganisms. ④ The identification of microbial community structure indicated that weathered coal contained the first and second stage bacteria needed to produce biogas,also had Methanobacteriales and Methanococcales,which had the environmental conditions for converting weathered coal into biomethane. The experimental results show that weath- ered coal has the potential to transform into biomethane,and is conducive to improving the utilization of coal resources in China.