Typical Fen-flavor uses ground-pot as the fermentation container. Studies show that ground-pot in the fermentation processes not only offers the place for fermentation,but has roles of leading warm and transmitting oxygen. In the same ground-pot,the temperature of center grains was about 6 ~ 7℃ higher than the grains close to ground-pot wall. During the 13-hour monitor,the oxygen concentration in the ground-pot raised from 0 to 500 μg / L or more,which might affect the propagation and distribution of microorganisms in the fermented grains,and ultimately affect the quality of liquor product. Microbiological analysis of fermented grains at different points in the ground-pot was performed using high-throughput sequencing. The results showed that some anaerobic and facultative anaerobic bacteria,such as Lactobacillaceae and Streptococcaceae,etc.,were dominated in the grains at the center of the ground-pot,while some aerobic bacteria such as Bacillaceae were majority in the grains close to ground-pot wall.