Based on the reservoir forming condition research of tight sandstone gas in Ordos Basin, Sichuan Basin and Tarim Basin, the authors give two types of tight sandstone gas reservoirs,sloped lithologic type and structural type which are the main of tight sandstone gas reservoir. The favorable gas region is predicted with multi-factor overlay method. And based on the existed tight sandstone gas reservoir analysis, the authors get the main parameters such as reservoir abundance, gas-bearing area coefficient which are necessary for gas resource calculation of the large basin through analogism method. According to the result of this resource evaluation, the tight sandstone gas geological recoverable resource in China is 9.2×1012～13.4×1012 m³ which is widely distributed over coal measure basins. The tight sandstone gas is the most realistic source in present. Due to the support of government policies and the motivation of technological progress, it might become one of the pillar sources in natural gas development in 10 to 20 years.