By means of experimental physical simulation, the influence of stress variation on the permeability of fractured and non-fractured ultra-low permeability sandstone cores were researched, the permeability variation of the two types of cores were compared with each other, and the stress sensitivity characteristics of the fractured and non-fractured reservoirs were summarized. The results show that for both fractured and non-fractured reservoirs, the lower permeability is, the stronger sensitivity of permeability stress is. For non-fractured reservoirs, when the reservoir permeability is lower than 2×10^-3μm², the sensitivity of permeability stress is strong and the strength increases rapidly as the permeability decreases, and when the reservoir permeability is higher than 5×10^-3μm², the sensitivity of permeability stress is weak; the fractured reservoirs stress sensitivity is much stronger than that for non-fractured ones; and the permeability loss of fractured reservoirs caused by the effective stress increase is 2—3 times of that for non-fractured reservoirs; and the permeability is unable to recover completely after the effective stress decreases, and the permeability loss of fractured reservoirs is 5 times of that for non-fractured reservoirs. The research findings are useful for engineers to determine the development strategy for ultra-low permeability sandstone reservoirs.