In order to investigate the characteristics of the airborne bacterial community in Changzhou's PM_2.5samplesduring spring, the 16S rRNA gene of bacterial in PM_2.5 sampleswas studied by high-throughput sequencing. 600150sequences obtained could be divided into 1890~6519 OTUs of each sample at 97% similarity level. The Coverage index of the samples was high and could accurately represent the airborne bacterial community in the samples. Species annotation results indicated that there were 11bacterial phyla, 14bacterial classes, 12bacterial genera with relative abundance greater than 1% in Changzhou's PM_2.5 samples during spring. Proteobacteria, Bacteroidetes and Firmicutes were the top 3dominant phyla, accounting for 80.88% of the total gene abundance. At the genus level, Chroococcidiopsis (6.03%), Rubellimicrobium (5.95%), Microcystis (4.86%) and Sphingomonas (3.16%) were predominant, but the proportion of gene sequences that failed to be classified was up to 81.11%. Based on the source analysis of bacterial community composition in PM_2.5, it was found that the environmental sources of bacteria in Changzhou's PM_2.5 samples during spring were varied, and the main environmental source might be fresh water, followed by soil, plants and anthropogenic sources. The results of redundancy analysis (RDA) for the relationship between environmental factors and bacterial community showed that NH₄⁺, NO₃^-, O₃, SO₄^2-, OC, air pressure and CO were the main environmental factors affecting the bacterial community in Changzhou's PM_2.5 samplesduring spring. At the same time, varied environmental factors had different effects on bacterial groups.