The phenomenon of liquid liquid equilibrium for products of transesterification reaction has been studied over the past decade. There was an increase of experimental data from different kinds of possible feedstock used to obtained biodiesel. Phase equilibrium data were presented here for systems containing soybean ethyl biodiesel, ethanol, glycerol, and water at 298.15 K. In addition, results on parameter estimation show a satisfactorily adjustment for experimental data with a UNIQUAC model, and a matrix with parameters was presented. The estimation procedure shows high sensibility for structural parameters of the UNIQUAC model. Therefore, new parameters were obtained for the system mentioned, which were capable of representing all experimental data measured at this work and data considered from the literature.