Abstract: The Southern Qinshui basin as an example, the CBM components, stable methane carbon and stable hydrogen isotopes produced by CBM wells during the different producing time from Fangzhuang block were tested by systemic sampling. The response characteristics of CBM components, methane stable carbon and hydrogen isotopes on the formation of well interference under group-well drainage in the monitoring CBM production area were analyzed by the analysis of the figures. The results suggest that the fractionation of CBM component and methane stable carbon and hydrogen isotopes of CBM have the characteristics of the fluctuating variation. The fractionation degree is affected by the degree of well interference on CBM wells. The instability of CBM source is related to the unstably regional fluid field and the relatively weak degree of well interference in CBM production area. The fractionation of methane stable hydrogen isotopes of CBM lags behind the fractionation of methane stable carbon isotopes because of the effect from the model of the fractionation mechanism of methane stable carbon and hydrogen in CBM, which indicates that the response degree from the fractionation of methane stable carbon isotopes is more sensitive than them from the fractionation of methane stable hydrogen isotopes.