The concentration profile of NaCl by the one dimensional diffusion with the FRITRUC method in pre-cooked egg white from the 3.0% solution was measured at 98℃. Fick\u27s diffusion coefficient, D, calculated therefrom was 2-4 × 10^cm^2s^ and showed a maximum near 0.07mol kg^-1. This variation was quantitatively interpreted by applying the dual mode sorption and diffusion theory developed for the dyeing of Nylon with some anionic dyes. Two thermodynamic diffusion coefficients, D_T(p) and D_T(L), where p and L means partition and Langmuir mode species of NaCl, respectively, a parameter, a, derived from the equilibrium relations between the p and L species, and S, the concentration of the Langmuir adsorption site in the egg white, were estimated. D_T(p) was found to be 2.2 × 10^cm^2s^ and D_T(L) was 2.5 × 10^cm^2s^. These results were discussed with reference to the NaCl diffusion in Japanese radish
