Bacteria community structure of different batches Daqu were studied by DGGE technique,The genomic DNA of Daqu was extracted directly by SDS-enzyme lysis.After the 16S rRNA genes(V3 region)were amplified by using universal primers,the PCR products were separated by denaturing gradient gel electrophoresis(DGGE),The profile of DGGE showed that bacteria community structure of different batches Daqu were similar,the phylogenetic analysis indicated that bacteria of Daqu were belong to Firmicutes,including Lactobacillaceae,Bacillaceae and Thermoactinomycetaceae.Besides,in addition to some bacterium which were discovered more often in fermented grains,there are other Uncultured bacterium in Daqu.