Abstract:The mixed culture fermentation properties of Bifidobacterium Pullorum B171 and Lactobacillus Acidophilus M16 were studied. The major result was follows: The optimized mix culture fermentation conditions of B171 and M16 were: pH value of media was 7.0, temperature was 40 ℃. The process of mix culture fermentation was inoculating B171 first and inoculating M16 6 hours later. The terminal time was 11 h after mixed culture fermentation.