The characteristics and kinetic modeling of carbon isotope of methane in Jurassic humic gas in Kuqa depression in Tarim basin have been studied by combining pyrolysis experiment in closed gold tube system and analysis of methane isotope with GC-IRMS isotope mass spectrograph.The carbon isotope ranges between -3.6%～-2.5% and is closely related to pyrolysis temperature (or vitrinite reflectance Ro) and heating rate. Kinetic simulation results of carbon isotope in humic gas methane are in good agreement with the experimental data

thus the experimental data can be extrapolated through kinetic modeling and applied to actual geological conditions. Simulation results show that natural gas in Kela 2gas field in Kuqa depression has mainly experienced episodic accumulation since 10 Ma (especially 5 Ma).