Abstract:［Objective］To reveal the relationship between bacterial community and the environmental in Zuohai lake，Fuzhou City．［Methods］The abundance of total bacteria was studied using DAPI staining; the composition，distribution and the dynamics of bacterial community were examined using both the denaturing gradient gel electrophoresis (DGGE) and the 16S rRNA gene clone library analyses over a 2-year periods from October 2011 to August 2013． Moreover，multivariate statistical analysis was used to analyze the relationship between bacterial community and environmental factors．［Results］The total numbers of bacteria ranging from 4.91×106 cells/mL to 18.71×106 cells/mL，and the seasonal variation of bacterial abundance was obviously stronger than the spatial heterogeneity． DGGE and clone library analysis revealed that bacterial communities were mainly affected by temporal changes． Phylogenetic analysis showed that bacteria belonging to 11 phyla were identified． Members of β-Proteobacteria and Cyanobacteria group were the predominated lineage，followed by α-Proteobacteria，Actinobacteria and Bacteroidetes． Redundancy analysis (RDA)suggested that water temperature，pH，total nitrogen，total phosphorus and chlorophyll a content contributed significantly to the bacteria-environment relationship．［Conclusion］There is rich bacterial diversity in Zuohai lake，the patterns of change in bacterial communities showed that the seasonal difference might have a significant impact on structuring the bacterial communities in the lake.