Bifidobacterium animalis is a lactic acid producing and anaerobic bacteria that has many health benefits especially in gastrointestinal health and immune functions. To be able to let B. animalis survive in food is to be co- cultured with bacteria that are not anaerobic. Lactobacillus bulgaricus and Lactobacillus plantarum are aerotolerant anaerobic and facultative anaerobic by order, and by co-culturing together with the B. animalis, it will stimulate the growth and able to survive. Currently there is no research of co-culture of B. animalis, L. bulgaricus and L. plantarum The objective of this study is to determine the best ratio (1:0:0; 1:1:2; 1:2:1; 2:1:1) of those three bacteria to improve B. animalis growth toward the total lactic acid bacteria and pH. The result showed that ratio 2:1:1 out 4 other ratios, is the selected ratio for co-culturing. The gradient log of 1:0:0 (control) is 0.0116 and the 2:1:1 is 0.4436 which is about 4 times more, and the pH of the 1:0:0 (control) is 5.62 and 2:1:1 is 3.97 which is almost half.