Bacteria in phycosphere of Microcystis affect growth, development and decline of Microcystis blooms. In specific Microcystis colony, however, the pattern of bacterial community composition in response to different temperatures are still unclear. In this study, a colonial Microcystis aeruginosa strain isolated from Lake Taihu was cultivated at different temperatures (15, 20, 25 and 30℃) to analyse the similarities and differences in the composition of different particle attached or free living bacterial communities in each culture system. Temperature significantly affected community compositions of bacteria including Microcystis colony (>20 μm) attached bacteria, single cell-small colony (3-20 μm) attached bacteria and free-living (0.2-3 μm) bacteria (PERMANOVA,P<0.01), Sphingomonadales, Pseudomonadales and Cytophagales were the most dominant order in the three groups, accounting for 21.35%, 19.74% and 33.44% of the total relative abundance, respectively. There were some core dominant bacterial species in the three groups of bacterial communities, which were relatively stable in abundance and insensitive to temperature changes. The relative abundance of Brevundimonas and OPB56, the dominant genus among the core bacterial community attached with Microcystis colony, were relatively stable when temperature changed from 20 to 30℃. The relative abundance of Mariniradius, the dominant genus among the core bacteria attached with single cell-small colony, was also relatively stable when temperature changed from 20 to 30℃, and the relative abundance of Gemmobacter, the another dominant genus among the core bacteria attached with single cell-small colony, was relatively stable in response to temperature changes. The relative abundance of Porphyrobacter, the dominant genus among the core bacterial community in free-living bacteria, were also relatively stable when temperature changed from 20 to 30℃. Compared with the situations at other three higher temperatures, the complexity of species correlation network at 15℃ was the highest but the cooperative correlation was the weakest. The results of this study were of great significance for understanding the algal-bacterial relationships in phycosphere of colonial Microcystis.