Abstract: Phosphorus (P) is an essential nutrient element for the growth of phytoplankton. However, excessive P loading can cause water eutrophication. Phosphate-solubilizing bacteria is an important factor affecting P regeneration and play a key role in P biogeochemical cycle in waters. To explore the effect of inorganic phosphate-solubilizing bacteria (IPB) on P release from the sediments at different areas of Swan Lagoon, we conducted a simulation experiment using two dominant IPB strains (Bacillus sp.) isolated from the central lake and surface sediments from four lake areas. The dynamic changes in pH, DO, total phosphorus (TP), and soluble reactive phosphorus (SRP) concentrations in the overlying water under different inoculations of IPB strains were analyzed. In addition, the effect of IPB on the transform of P fractions in sediments was determined. The results showed that the DO concentrations and pH in the overlying water decreased at different degrees, and the sediment-water interface quickly reached an anaerobic condition during the experiment. The IPB inoculation promoted the release of P from the sediments of Swan Lagoon, and IPB strain and lake area both had significant effect on TP concentration of the overlying water. SRP concentrations in overlying water under different incubation treatments ranged from 0.009 to 0.666 mg/L. There was considerable difference in the ability of two strains to solubilize phosphate in the sediments from different lake areas. The Bacillus flexus had the strongest phosphate-solubilizing ability under the treatment of the northwest lake, and the SRP concentration in the overlying water increased by 0.510 mg/L. Bacillus megaterium had the strongest phosphate-solubilizing ability under the treatment of sandy sediment in the south lake, with a SRP increase of 0.583 mg/L. At the end of the experiment, the NaOH-P content in sediments decreased in B. flexus inoculation group, ranged from 2.49 to 30.36 mg/kg, with the greatest decrease in the northwestern lake. BD-P content in the southern lake decreased under different inoculation conditions, and the decrease was greater in the B. megaterium group than that in the B. flexus group. Whereas, the content of other P forms in sediments did not change significantly. The inorganic P contents in sediments varied greatly at different areas of Swan Lagoon, with high values occurring in the central and northwestern lake. The results indicate that the P release capacity of the sediments differed across different lake areas after the IPB inoculation, and the highest effect of microbial activity on P release was observed in the sediments from the northwestern lake. In Swan Lagoon, the contribution of IPB to sediment P release at this area should not be ignored.