Abstract: Tight sandstone gas and shale gas are currently two major unconventional hydrocarbon resources, which will be the significant resources for replacing the conventional oil and gas in next 10 to 20 years. Despite the understanding of geological property, or the technology of exploration and development, tight sandstone gas will be easily realized than shale gas in the next 10 years. However, precise prediction of favorable reservoir space has become a bottleneck for current tight sandstone gas exploration and development. Clarifying the deposition-diagenesis genetic mechanism of tight sandstone reservoir is the key to solve this problem. According to the research on the typical tight sandstone gas fields in China and data analysis abroad, tight sandstone generally deposited under weak hydrodynamic stability and relatively low depositional rate that much developed in coal-bearing（thin bed interbedded） strata of the transitional environments or deltas. Hence, these depositional mechanisms facilitate the requirement of forming tight sandstone. Continuous compaction during early diagenetic stage is the main process for their tight nature. The complex burial history under low geothermal gradients which were caused by multi-cycle movements of basin is the sufficient condition for forming tight sandstone reservoirs. Therefore, abnormal pressure zones in multi-cycle pre-Tertiary basins with low geothermal are the favorable area for exploring tight sandstone gas. The sandstones with thin interbedded coal-bearing strata in delta front are primary exploration and development intervals. Heterogeneity characteristics of tight sandstone play an important role on reservoir exploring and evaluating. The effect of microscopic pore structure change on permeability should be studied for evaluating pay reservoirs property. “Permeability blind area” and abnormal pressure data were employed for evaluating quality of reservoir. On the basis of this idea, we proposed six prospective areas for tight sandstone exploration and development in China in future.