We have study the low temperature phase diagram of a lattice model of the micellar binary solutions (MBS) of water and amphiphile. The mean field approximation is used to investigate the phase diagrams of the micellar binary solutions in the presence of a chemical potential of the amphiphiles for different values of coupling interactions. New phases appear between water-rich and amphiphile-rich. Second and first order transitions, tricritical, multicritical and critical end- points are obtained, by a simple low temperature expansion argument. We have confirmed the states of lowest free energy in a mean field approximation.