Abstract: In order to study the influence of formation pressure change on permeability and porosity of low permeability reservoir, the conventional stress sensitivity experiment and simulated stress sensitivity experiment caused by formation pressure drop during gas reservoir development were carried out respectively. The experimental results show that the relationship between effective stress and porosity and permeability is a power form, and the stress sensitivity of permeability is stronger than that of porosity.Water saturation has great influence on the stress sensitivity of permeability. Under the same net stress, the gas permeability decreases with the increase of water saturation.