Abstract: Tight gas reservoir is characterized by complex pore structures and gas?water percolation flow pattern, which allows its deliverability evaluation to be influenced by many factors. Under the available conditions of the pore structure, fluid viscosity and volume factor, the gas?water flow could be more influenced by water lock starting pressure gradient and stress sensibility, thus resulting in more influence on its deliverability of gas wells. Taking XX4gas well in eastern Sulige gas field of Changqing oilfield as an example, this paper develops the model for the fluid flowing deliverability, analyzes the effects of water lock starting pressure gradient and stress sensibility on the tight gas reservoir’s deliverability based on two?phase flow theory, which plays a positive role in guiding accurate prediction and evaluation of the deliverability of tight gas reservoir