Abstract: By means of permeating tests of rock under triaxial compression, the permeability rule in full strain-stress process has been studied. It is found that the permeability coefficient is generally not a constant, but varies with the inner structure evolution of rock in full stress-strain process. The highest permeability occurs mostly in strain softening period. The results indicate the importance of both controlling fracture occurrence and deformation development after rock failure in prevention of water in-rush catastrophe.