A mixture of 0.8 M D-xylose and 0.8 M glycine, when heated at 100°C, showed inhibitory effect against autoxidation of 40% ethanol solution of linoleic acid. The antioxidant activity increased in proportion to color intensity of browning reaction solution, whereas reductones formed during the browning process showed little contribution to the activity. Nondialyzable melanoidin fraction of browning solution also showed a positive activity. Consequently, it was considered that melanoidin pigment would play an important role in the antioxidant activity.