Abstract: Tight sandstone gas is the main type and the direction of development of unconventional gas in China. Study on the mechanics and factors for tight sandstone gas reservoir damage is more favorable to reservoir protection during the reservoir development and field operation. This paper presents the geological characteristics of the Ahe tight sandstone gas reservoir of Jurassic in Dibei area of Tarim basin, analyzes the potential factors of reservoir damage caused by pore structure and clay minerals, and makes the experiments of reservoir sensitivity and aqueous phase trapping. The results show that there exist such damages as moderate?strong water sensitivity, medium?strong fluid velocity sensitivity, medium acid sensitivity and larger aqueous phase trapping in the Ahe reservoir, and it is suggested that the well fluid type, flow rate and other related properties should be controlled, and acid liquid should be used very carefully for the purpose of efficient development of such a gas reservoir