Mulberry (oddi) is one of the most popular functional foods with many physiological components. This study investigated and compared the nutritional compositions and physiological activities of four mulberry fruits from Morus albo L. including Cheongilppong, Iksuppong, Suwonppong and Cheongsuppong (a new cultivar from Chungcheongbuk-do). To analyze the nutrient contents, mulberry fruits were freeze-dried. The results showed that the proximate compositions of the four mulberry cultivars ranged from 9.61~14.11% for moisture, 8.28~11.90% for crude protein, 3.70~4.86% for crude ash, 4.28~5.54% for crude lipid and 7.46~10.78% for crude fiber. The above proximate contents of mulberry cultivars were not significantly different. However, Cheongsuppong had the highest content of reducing sugar, 74.7%. Chungsuppong and Iksuppong showed higher contents of total polyphenol and anthocyanin than other mulberry cultivars, while all mulberry cultivars showed high antioxidant activities. Hypoglycemic effect had a slightly higher level in Suwonppong and Cheongsuppong than in the other samples. Taken together, the new cultivar “Cheongsu” oddi can be suggested as a potential source of functional food.