In order to understand whether the total number of bacteria and yeasts in Tibetan kefir grains was subjected to change by using qPCR method, their genomic DNAs were prepared successfully by adding lysozyme and lyticase simultaneously. Subsequently, qPCR was performed. It revealed that the gene copy number of bacteria (16S rRNA gene) and yeasts (26S rRNA gene) was 10⁷ copies/μL and 10⁵ copies/μL respectively after 1, 4, 8 and 12 week(s) of cultivation, which indicates that the communities of bacteria and yeasts are relatively stable in Tibetan kefir grains. These results give an insight into exploration of symbiosis mechanism between bacteria and yeasts in Tibetan kefir grains.