Abstract:The structure of saturated porous body with low permeability deforms under uniaxial compression load and the liquid in porous is compressed also. The part of compressed pore liquid penetrates throughout the micropipe of body. The pore liquid pressure supporting load is reduced and the load is moved to the solid structure. Thus the equilibrium takes place finally after a serious loading redistribution,reduction of pore pressure and increment of structural deformation. In present paper,the variation progress of pore pressure and structural deformation in saturated weak rock,and changes of saturated bulk modulus are given,which are confirmed by the results of experiments.