In order to discuss the role and influence of water during the generation of natural gas,the participation mechanism of water during the evolution of organic matter and its influences were summarized.In addition,we carried out an anhydrous cracking experiment of oil extracted from the Feixianguan Formation source rock in a closed system,which led to the establishment of the kinetic models for describing carbon and hydrogen isotopic fractionation during gas generation from organic matter.The models were c...