The optimum conditions for lactic acid fermentation by Lactobacillus acidophilus in the media containing malt syrup, skim milk or skim milk and malt syrup were studied to develope marketable fermented beverages from barley. The optimum sugar concentration of malt syrup was 10℃ Bx. Addition of skim milk to malt syrup enhanced bacterial growth and acid formation. The best flavor of the product was obtained from the media containing 5% skim milk and sterilized at 90℃ for 30 minutes. Optimum temperature and pH for the formentation were 40℃ and 6.0, and bacterial cells grew logarithmically upto 16 hours.