Abstract:［Objective］The aim of this study was to analyze the bacterial diversity of urban section of Nanming river as well as to study relationship between the bacterial diversity and environmental factors.［Methods］The high throughput sequencing on PCR-amplified 16S rDNA V4 fragments was used to determine the bacterial diversity of samples from five sites of Nanming river．The ordination technique of redundancy analysis was used to analyze the effects of the environmental factors on bacterial community composition.［Results］ Diversity index analysis of bacterial community composition in Nanming river showed that the Shannon-Wiener index of bacterial diversity in Nanmng River was about 7.5．The Shannon-Wiener index of 5 sampling site had an order as Wudang bridge＞Shuikou Si＞Wuyan bridge＞Huaxi bridge＞Guanzhou bridge．Based on the sequencing results，there were 11 phyla (327 genera) in the samples，of which proteobacterice (66.1%±3.30%) was the dominant phyla，Gamma proteobacteria (54.76%±4.86%) was the dominant subgroup and Pseudomonas (16.92%±0.02%) was the dominant genera．In addition，there are some flora and rare flora undetermined． The result of RDA suggested that the influence of different environmental factors on different microbes were different． Bacterial community Ⅳ had significant positive correlation with total nitrogen and total phosphorus in the environment.［Conclusion］This research provides references for the association of bacterial composition and diversity with environmental factors.