The study of rock and water interaction is very important for not only on the theory but also on the engineering practice; the anisotropic characteristics and hydraulic properties of rock mass is used in oil exploitation
radioactive waste storage etc; and then the hazards are often from the water softening
. Based on the microscopic analyses
the energy principle of anisotropic damage and fundamental equation of Biot’s coefficient are established; the two testing methods of obtained isotropic Biot’s coefficient are proposed. They are proved to be available to determinate the Biot’s parameter by sand laboratory
and anisotropy of Biot’s coefficient is also proved by the stress-strain complete process curve of triaxial compressive tests with injecting and drainage. The anisotropy of Biot’s coefficient is very important for injecting and grouting in civil engineering.