The high-gas and low-permeability are the common problems of China coal mine, which restrain the mining of coal resources safely and efficiently. To solve the low permeability of coal-seam, the variation of permeability was studied experimentally with coal effected by supercritical CO 2 and low-carbon alcohol solution (including methanol solution, ethanol solution and isopropyl alcohol solution). The results show the permeability of coal after injecting supercritical CO 2 is nearly one order of

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... magnitude over former testing. This is principally resulted from that supercritical CO 2 will extract some organic matters of coal substrates. Meanwhile, the permeability of sample effected by low-carbon alcohol solution is apparently higher than former experiment without solution. Moreover, the bigger volume concentration to certain low carbon alcohol solution, the greater the permeability will increase. As to the three different low-carbon alcohol solution, the isopropyl alcohol solution has a biggest influence on improving coal permeability, whereas the methanol solution has a smallest one. China has the third coal reserves in the word, with 98900 million tons recoverable coal reserves meanwhile 36.7 trillion tons coal bed gas reserves. However, the structure of the coal seam in China mainly belongs to hyposmosis coal seam, which makes the difficulty for exploiting the coal bed gas [1, 2] and would be harmful for the prevention of coal gas accident. Therefore, in order to improve the recovery ratio of the coal bed gas and reduce the possibility of the gas accident, it is necessary to study how to increase the permeability of the coal, meanwhile national and international experts have done many