Abstract: In order to investigate the core floras in traditional fermented dairy products, 454 pyrosequencing was used to analyze the microbial abundance and the community diversity in the traditional fermented yogurt, koumiss and kurut samples in present study. The result showed there were core floras in three traditional fermented dairy products. The number of OTU of this flora part was less, but exists a large number of sequences.Firmicutes was the dominant phylum of bacterium and Ascomycota was the dominant phylum of fungi in the three samples. At genus level, Lactococcus was the dominant genera in bacterium and Galactomyces was the dominant genera in bacterium in the yogurt sample. Lactobacillus and Vanderwaltozyma were there respectively dominating bacteria and fungi, in the koumiss sample.And Lactobacillus was the dominant genera in bacterium and Galactomyces was the dominant genera in bacterium in the kurut sample. At the same time, the relative abundance of Lactococcus and Galactomyces, Lactococcus and Leuconostoc core floras existed significantly negative correlation(p<0.05), Leuconostoc and Galactomyces, Gibberella and Prevotella existed significant positive correlation(p<0.05)in three traditional fermented dairy products common floras. The result showed that core floras were exist in three taditional fermenterd dairy products and they had correlations with each other.