Based on the capillary phase-separation concept, or a hindered liquid-liquid equilibrium in narrow pore with curved interface, a method for pore characterization of solids immersed in solvents was proposed. The method is considered to be effective for determination of pore characteristics of swelling/shrinking solids in solvents. The method was tested by comparing the pore size distribution calculated from liquid phase adsorption isotherm and that from nitrogen adsorption on a non-swelling solid. The distribution from liquid phase was able to express the pore characteristics satisfactorily to show the potential power of the method proposed The parametric sensitivity of the method and desirable nature of the probe molecule are also discussed.