The bacterial diversity and phylogenetic analysis of two hot springs in Chengde were investigated and analyzed by construction of 16S rRNA gene clone libraries. The results showed that bacteria in sample A11 (68 °C) could be divided into 5 groups, which were as follows: Firmicutes (6.25%), Deinococcus-Thermus (25.0%), Gammaproteobacteria (12.5%), Betaproteo-bacteria (50.0%), Al-phaproteobacteria (6.25%). But sample A12 (74.5 °C) contains only one group, Firmicutes. The differ-ence between the two samples revealed that the temperature was an important factor to affect the level of bacterial diversity in hot springs. Furthermore, a lot of 16S rDNA sequences in A11 clone library had high similarity to the aerobic bacteria that can produce pigment, while most bacteria in A12 clone li-brary belonged to obligate or facultative anaerobe, in which, Anoxybacillus flavithermus can be used as ideal material to research the formation of sinter.