After gas component and methane carbon isotope were analyzed from cores at different depths in DK-8 gas hydrate drilling hole in the Muli permafrost of the Qilian Mountain, their features changing with depth were correlated with intervals of gas hydrate & anomalies, and with spatial distribution of faults or fractures; their indicative significance was finally pointed out to gas hydrate occurrence and hydrocarbon migration. Gas contents (µl/kg) in cores behave their heights at intervals of 149~167m, 228~299m, 321~338m and 360~380m, which were basically consistent with intervals of gas hydrate and its anomalies, suggesting that high values of gas content were caused by gas hydrate and its anomalies. Total volumetric percentage of hydrocarbon gases in core (vol%), carbon isotope of methane (δ13C1, ‰PDB), and ratios of C1/ƩC1-5, C1/ΣC2-5, C1/ΣC2-3, C1/C2, C2/C3, C2/ΣC3-4, iC4/nC4 and iC5/nC5 from samples with different distance away from faults or fractures, indicated that hydrocarbon gases in cores with high value features which represent gas hydrate and its anomalies, were mainly migrated from deep sources and were closely related with faults or fractures; deeper faults or fractures may serve as migration paths for hydrocarbon gases, and middle to shallower faults or fractures may provide accumulation space for gas hydrate.