Omija, the major material of omigalsu, has liver protective and antioxidant effects, while mung bean has detoxification effects. A series of studies were conducted to standardize the traditional recipe for omigalsu to develop traditional functional drinks made from Omija extract and mung bean juice. Study 1 was designed to determine the optimal conditions for Omija extraction and mung bean juice. A higher water temperature and longer immersion time was associated with higher, free sugar and organic acid contents of omija extract; however, sensory evaluation revealed that the optimal extraction conditions for the highest acceptability, proper taste and red tone were $23^{circ}C$ and 18 hrs of immersion. Conversely, the pH of the mung bean juice produced by varying the immersion time (5 hr, 11 hr, 17 hr) was found to be neutral, containing small levels of organic acid and free sugar, and showing a yellow tone. The results of the sensory evaluation also showed that the optimal conditions for taste, flavor and yellowness of mung bean juice was 5-hour-long immersion. Study 2 was designed to determine the optimum mixing ratio of omigalsu concentrate. Sensory evaluation revealed that the contents of sugar and total free sugar were highest when the mixing ratio among omija extract, mung bean juice and sugar was 1:1:20%, indicating that these conditions produced the most attractive color and highest overall acceptability. Study 3 was designed to determine the optimum dilution magnification for omigalsu. Sensory evaluation during summer revealed that the omigalsu produced by mixing 54 g of omigalsu concentrate into 200 cc water of $4^{circ}C$ or $80^{circ}C$ was most preferred, while during winter. Overall, the optimum dilution magnification for omigalsu was 4.7~5.4.