Bacterial biodiversity of the hot spring Dagunguo in Tengchong Rehai in Yunnan Province, China was preliminarily studied with culture-independent method. Five complete 16S rDNA sequences were obtained and phylogenetically analysed. Four of these sequences were closely related to the genera: Bacillus, Hydrogenobacter and Pseudomonas, and the other one was clustered with the Family Thermodesulfobacteriaceae between an unpublished genus Geothermobacterium and Thermodesulfobacteria. The V8 high variable region(about 600bp) of 16S rDNA from the five 16S rDNA sequences and the genomic DNA were obtained by PCR. All of the PCR products were run DGGE. The pattern of DGGE and the phylogenetic tree of the five sequences not only indicated the hot spring Dagunguo of Yunnan province has plenty of bacterial species but also showed they were dominant bacterial species in the hot spring.