Abstract: The majority of gas reserves in China are stored in large and giant coal-related gas fields coal-related gas.Despite the fact of numerous coal-bearing basins in China,there are only a few large-and medium-sized such basins having the right geological conditions for forming large or giant gas fieds.The tectonic geological environments after deposition of coal-bearing strata are thought to be more closely linked to coal-related gas reservoirs:the later the peak gas-generation and reservoiring periods were,the more favorable it was for coal-bearing basins transforming into gas(oil)-bearing basins and forming larege and giant coal-related gas fields.Coal-bearing/gas(oil)-bearing basins of para-foreland type,intracratonic depressions type and marginal rift type are considered to be most promising in terms of exploration for gas.Basins including Ordos basin,central,western and north-eastern Sichuan basin,northern Tarim basin(Kucha depression),Xihu sag in East China Sea basin,Yingqiong basin and northern Chaidan basin as well as those in Sanhu area,northern and southern Junggar basin,the deeper part of Songliao basin,basins in deep water area of northern South China Sea,will still be the major hope for near and middle term gas reserve growth in China for the century.

Key words: distribution pattern of gas fields, large and giant gas field, coal-related gas, coal-and gas(oil)-bearing basin, China