The seed globulins from Vicia faba predominantly consist of two components, vicilin and legumin, which are exclusively deposited within the protein bodies of the storage cotyledons. The globulin biosynthesis commences with high intensity within a distinct phase during seed development as a consequence of reactivated genetic information. Isolation and purification of vicilin and legumin were achieved by a combination of zone precipitation, ion exchange chromatography, and gel filtration. Purity was controlled by disc electrophoresis on polyacrylamide e gels at pH 4.3 and by two dimensional immunoelectrophoresis, respectively. Vicilin prepared by zone precipitation and ion exchange chromatography consists of several serologically different proteins. One of them occupies the legumin position on polyacrylamide gels, although not identic with legumin, as revealed by tandem immunoelectrophoresis. The serological nonrelationship of vicilin and legumin was confirmed. Vicilin is characterized by micro heterogeneity which seems to indicate a molecular polymorphism.