We have investigated for amino acid composition and molecular weight of the sunflower main protein which was purfied by Sephadex column. The results were obtained as fellow. 1. The salt-soluble sunflower proteins were highly dispersible in 0.02M sodium phosphate buffer, containing 10% sodium chloride. 2. The sunflower proteins were characterized by comparatively high levels of essential amino acids. 3. Seven bands of component of sunflower proteins were found in disc electrophoretic gel column. 4. The sunflower main protein was purified by Sephadex G-150 and A-25 column chromatography 5. The molecular weight was estimated 86,000 for the sunflower main protein.