The composition of carbon isotope in shale gas is in inversion with the carbon number distribution patterns all over the world. For example, shale gas that is widespread worldwide possesses carbon isotopic composition of the inversion occurrence with the carbon number distribution patterns. Examples are as follows: The four main shale gas production regions are the Barnett, Woodford, Haynesville, and Fayetteville in America and the Appalachian shale gas production region in Canada. They comprehended phenomenon [4], [5], [6], [7] and [8] of gaseous hydrocarbon carbon isotopic inversion confirms that most of the carbon isotope inversion are related to the production of shale gas, which can indicate the “core” region of shale gas [5], [6] and [8]. The reason behind carbon isotope inversion of the dragon stream group in Sichuan Basin still lacks systematic research, and it requires further investigation to find out whether it is related to the shale gas production.