Canavanine content of the cotyledons of Canavalia lineata decreased gradually during germination and growth of seedlings but continued to increase in roots and leaves. After abscission of cotyledons, canavanine content of leaves depleted competely. The activity of canavanase could be detected in leaves and roots, but not in cotyledons. High arginase activity was observed in the cotyledons of seeds at the earlyimbibition period. During the growth of seedlings, cotyledonary canavanine appeared to be transported to the growing of seedlings where it could be utilized through nitrogen metabolic pathways. In crude cell-free extracts of leaves, maximum activities of canavanase or arginase appeared in 30mM Tris-HCl buffer (pH 9.0) or 30mM NaHCO3 buffer (pH 10.0), respectively. The activities of these two enzymes differed from each other when treated with Co2+ or Mn2+. These results support the idea that canavanase and arginase might be different enzymes.