PURPOSE: A method of manufacturing fermentative beverage of Rubus coreanus is provided to manufacture fermentative beverage of the Rubus coreanus with a high content of functional components such as anthocyanin, flavonoid, and total phenol compounds. CONSTITUTION: Fermented Rubus coreanus liquid 1-20 parts by weight, saccharides 5-15 parts by weight, organic acid 0.01-1.5 parts by weight, fruit concentrate 1-5 parts by weight, and purified water 100 parts by weight are mixed and sterilized. The fermented Rubus coreanus liquid is obtained by inoculating 0.1-1.0 wt% of lactobacillus compared to the weight of Rubus coreanus to Rubus coreanus juice or a Rubus coreanus extract, and fermenting the mixture at 35-42 deg. C for 1-3 days. The lactobacillus is any one selected from Lactobacillus plantarum, Lactobacillus bulgaricus, Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus casei, Lactobacillus delbrueckii, Lactobacillus helveticus, Lactobacillus sakei, Lactobacillus fermentum, and Lactobacillus gasseri. The saccharides is any one or more selected from sugar, glucose, fructose, rice candy group, starch syrup, sugar syrup, dextrin, oligosaccharide, malto-oligosaccharide, isomalto-oligosaccharides, cello-oligosaccharide, fructo-oligosaccharide, inulo-oligosaccharides, galacto-oligosaccharide, chitosan-oligosaccharide, xylo-oligosaccharide, honey, propolis, trehalos, sorbitol, xylitol, mannitol, mantitol, rhamnitol, inositol, erythritol, paratinose, and quercitol. The organic acid is any one or more selected from citric acid, fumaric acid, malic acid, tartaric acid, and sodium citrate. The fruit concentrate is any one or more selected from apple concentrate, lemon concentrate, citrus junos concentrate, tangerine concentrate, orange concentrate, pear concentrate, strawberry concentrate, kiwi concentrate, banana concentrate, watermelon concentrate, oriental melon concentrate, melon concentrate, grape concentrate, peach concentrate, apricot concentrate, plum conc
