Abstract: The reservoir pressure will change as a result of development of low-permeability gas reservoir, which lead to change of porosity and permeability. Through experiment, it is shown that porosity changes quite a little, whereas permeability varies more relatively. It avoids higher estimate of permeability damage resulting from formation compaction to use the data for analysis of second increase-decrease stress sensitive experiment, which suits production practice better. Analyzing core of low-permeability gas reservoir, stress sensitive index of higher permeability core is greater than that of lower one. That is because small-size porous channels in the former close are more seriously than the latter. And the permeability danage induced by formation compression can be recovered.