Abstract：The large-strain description method for the constitutive equation of fluid flow in fluid-solid coupling theory is studied for different reference configurations. Using the coordinate transform method，the strain tensor transformation relation and the objectivity hypothesis，the rational forms of Darcy¢ law in both spatial description method and material description method are derived respectively，as well as the seepage coefficient expression for large-strain deformation coupling. The results of both experimental and case analysis show that the differences of seepage coefficients between different description methods increase with the development of material deformation；and the ignorance of the effect of reference configuration for large-strain problems will lead to a considerable big error. The large-strain seepage coefficient(FSSC) considering deformation coupling is greatly influenced by both material and geometrical nonlinearities. The behavior of mathematical monotonicity for FSSC is more complex than that for the large-strain seepage coefficient.
