This article considered individual and unidirectional cooperative mass transfer of two components with a various in the surface-active properties in extraction system carbon tetrachloride - 4% aqueous solution of potassium iodide in the flat interface in the conditions of spontaneous interphase convection. Studied the interaction flow of components in unidirectional cooperative mass transfer on the intensity of mass transfer each other in the conditions of spontaneous interphase convection. Unidirectional cooperative mass transfer acetic acid and iodine increase mass transfer iodine coefficient as compared to its individual mass transfer.