The weight-loss characteristics of Longkou lignite were studied by means of thermogravimetric analysis in methane ambience. Pyrolysis experiments of the sample coal in different concentrations of methane were carried out on a tube reactor to study the characteristics of hydrocarbon released. The results show that methane can promote the pyrolysis of lignite in a certain temperature range and the coal can also improve the pyrolysis of methane further. The influence of methane concentration on hydrocarbon release during the pyrolysis of coal is obvious. The hydrocarbon released from the pyrolysis of lignite is intensive within the temperature range from 400 ℃ to 500 ℃ and the release of hydrocarbon components dramatically increased as the concentration of methane decreased. This indicates that the release of C2, C3 and C4 has a close relationship with methane pyrolysis and proves that a synergistic effect does exist between the coal and methane.