reported the increased scavenging activity of fermented milk may also be related to milk protein and soybean protein-derived peptide. McCue and Shetty (2005) suggested that the increasing of antioxidant activity during soy milk yogurt production using kefir cultures may be due to the mobilization of phenolic compounds. Phenolic compounds are plant-based materials, phytochemicals. In this study, the increasing of antioxidant activity of the rice milk-kefir may be correlated to these compounds. The high inhibition percentage of antioxidant activity of rice milk-kefirs similar to inhibition percentage of BHA activity. BHA is known to be effective antioxidants (Madhavi et al., 1996). Due to their scavenging abilities on free radicals, rice milk-kefir A and B might possess good antioxidant properties. These findings have suggested that rice milk-kefir A and B are potential candidates for the role of useful natural antioxidant supplements for the human food.