This study was undertaken to evaluate the quality characteristics and antioxidant characteristics of commercially available mixed grains in Korea. The quality characteristics of mixed grain products studied were the mixing ratio, water binding capacity, water solubility, swelling power, and pasting characteristics. The antioxidant characteristics assessed the total polyphenol, flavonoid contents, DPPH and ABTS radical scavenging activities. The mixing ratio of commercially available mixed grain products consisted of 5~25 kinds of grains, with maximum products containing 15-grain products. The water binding capacity, water solubility, and swelling power in commercially available mixed grain products were 99.83~122.83%, 6.91~39.26% and 7.76~86.92%, respectively. The peak, trough, breakdown, final and setback viscosity were 31.53±20.17 RVU, 25.24±13.22 RVU, 6.29±7.43 RVU, 50.27±25.84 RVU and 18.74±8.68 RVU, respectively. Total polyphenol and flavonoid contents were 817.14~2,524.29 μg GAE/g and 06.36~1,099.09 μg CE/g, respectively. The DPPH and ABTS radical scavenging activities were 31.91~151.70 mg TE/100 g and 28.09~119.92 mg TE/100 g, respectively. Products with high phenol content and radical scavenging activity were found to contain greater proportion of brown rice, colored rice, barley and soybean.