Abstract: The tectonic evolution and formation mechanics of coalbed gas reservoir in Zao-yuan area, southern margin of Qinshui Fault Depression, Shanxi, are researched. The results indicated that the coal reservoirs of Shanxi Formation primarily underwent two times tectonic evolution, such as the pressing from E to W in the stage of Yanshan and the extension from E to W in Himalayan epoch. The tectonic evolution has controlled the burial history, heating history and hydrocarbon generation history of coal beds, and influenced the formation & evolvement of coalbed gas of Shanxi Formation in the research area.