Phaseolus coccineus storage globulins were extracted from mature cotyledons, purified and characterized. Three major proteins were separated. A component showing erythroagglutinating activity was thoroughly purified by thyroglobulin-Sepharose chromatography. The relative molecular masses of the three fractions are Mr = 330, 178, and 500 kDa as determined by polyacrylamide gel electrophoresis (PAGE). They correspond to the proteins found in other systems and classified as phytohaemagglutinin (PHA), vicilin and legumin, respectively. Electrophoretic analyses under denaturating conditions (SDS-PAGE) evidenced the major subunits for the three proteins. Isoelectrofocusing of the isolated proteins indicated a large heterogeneity for vicilin