The performance of the hollow fiber reverse osmosis module is analyzed using a membrane transport equation based on the theory of irreversible thermodynamics. Three membrane properties of the irreversible thermodynamics model are estimated by the curve-fitting method using experimental data from a mini-fiber module, while the mass transfer coefficient is quoted from the authors' previous correlation equation. As a result, the membrane properties such as L-p and P-m show quite reasonable values in comparison with the A and B values of the Solution-Diffusion model, and the calculated result of the module model is in good agreement with the actual performance data. Finally, the meaning of the solute convective coefficient gamma is discussed quantitatively.