A two-dimensional mathematical model is used to elucidate the mechanism of protein transfer from an. aqueous phase to a reverse micellar organic solution. The model gives the relative degree of encapsulation of a protein by the interface in response to the electrostatic interactions between them. The effect of parameters, such as charge density and charge distribution on the protein, ionic strength of the solution, and size of the protein and initial distance of the protein from. the interface, on the deformation of the interface and relative mass-transfer was studied. The model qualitatively predicts the general trends of protein extraction into reverse micellar solutions.