A series of permeability tests of sandstone under different confining stresses and seepage pressures were carried out by using a servo-controlled rock mechanical test system named TRIAXIAL CELL V3.The test results indicate that the permeability of sandstone varies with confining stress and seepage pressure.On one hand

the permeability increases with seepage pressure under the same confining stress

and the results show that for small confining pressure permeability pressure has a great influence on permeability.On the other hand

the confining stress-permeability curve of sandstone has the same variation trend at the same seepage pressure.The permeability decreases with confining pressure due to the closure of microfissures.Furthermore

the fitting equations are presented for interpreting the relationship between permeability and confining pressure.