Abstract: To increase the total number of viable bacterias in the lactic acid bacteria culture, a peptone was used to replace nitrogen source in a competing product for lactic acid bacteria culture. The method of microbial broth turbidity and microbial viable count was used to determine the result of the culture. The result showed that when the peptone as a nitrogen source was used to culture Streptococcus thermophilus, Lactobacillus plantarum, Lactobacillus casei and Bifidobacterium in the medium, the turbidity and the total number of viable bacterias were higher than the competing product. But when culturing the Lactobacillus bulgaricus, the result was worse than the competing product. When using a peptone to culture the majority lactic acid bacterias, the result was superior to the competing product. Insteading of partial nitrogen source of the competing product, the peptone could be used as a new culture nitrogen source and reduce the production costs of the medium.