This study aimed to evaluate the fermentation characteristics of mixed Makgeolli with barley and wheats under, fermentation at different temperatures (20, 25, and 30℃) and time (3, 6, and 9 days). The pH and sugar of mixed Makgeolli were 3.68~4.26 and 12.30~17.31 ∘Brix, respectively. The total acidity showed proportionate increase with fermentation temperature and time; whereas, reducing sugar contents decreased with increasing fermentation temperature and time. The alcohol contents of mixed Makgeolli varied significantly by fermentation temperature and time (p<0.05). In terms of color values, the L value decreased with increasing fermentation temperatures, and a value increased significantly with increasing fermentation time. The number of microorganisms (yeast, total bacteria and lactic acid bacteria) in mixed Makgeolli decreased progressively with increasing fermentation temperature and time. Among the organic acids (citric, lactic, malic, and pyruvic acids) in mixed Makgeolli, citric and lactic acid was present at the highest concentrations. From these results, the optimum fermentation conditions of mixed Makgeolli with barley and wheat were 20~25℃ for 6 days.