Abstract: The transfer of water through the organic phase of kerosene containing surfactants Span80, L113B and certain carriers was studied theoretically and experimentally in (W/O)/W LSM. The process of swelling owing to osmotic pressure can be pictured as solubilization of water in the membrane phase caused by surfactants and carriers and then its diffusion through the membrane between the two aqueous phases due to a gradient of chemical potential. The data of solubilization of water in oil caused by surfactants and carriers were measured. A mathematical model containing no adjustable parameters for estimating the "permeation swelling" rate, Fso, was developed. The predicted values agreed well with the experimental data of Fujinawa (1984), Ma Xin-sheng (1987) and the authors.