Abstract：The off-flavor issue of water attributable to the odorous compounds released by algae has become one of the world's water environmental problems， and has aroused widespread extensive public concern. Using the laboratory experiments， this study investigated the effects of phosphorus （P） on the release of odorous substances - β-cyclocitral （β-cyclocitral） from eight common Microcystis species. Results showed that P was able to significantly influence the growth and release of β-cyclocitral of Microcystis. In particular， medium and low P concentrations （0 ~0.5 mg·L-1） were beneficial to the growth of most species of Microcystis， while the effects on algal activity （Fv/Fm） were not consistent with that of chlorophyll a. The ability of Microcystis aeruginosa to release β-cyclocitral was proportional to the P concentration. The Microcystis aeruginosa was found with the highest β-cyclocitral yield rate （β-cyclocitral/Chl-a， up to 34.2 ng·μg-1）， followed by Microcystis elabens （24.1 ng·μg-1）， and Microcystis wesenbergii was observed with the lowest β-cyclocitral yield rate of only 0.21 ng·μg-1. Data analysis indicated that the large disparities in the release of β-cyclocitral under various P concentrations among different species of Microcystis were strongly related to their β-cyclocitral yield rates， and the latter were also associated with the algal activity. The field data also demonstrated that with the increase of P concentration in eutrophic lakes， more β-cyclocitral was released by Microcystis aeruginosa， which was in line with the results of our laboratory experiments. Through laboratory experiments， this study revealed that the varied effects of P on the growth and activity of different Microcystis， which was the main contributor for the release of β-cyclocitral by different Microcystis. Our study illustrated that P is an important factor regulating the release of β-cyclocitral by Microcystis， which is of great significance for the prevention and control of odorous substances in eutrophic water.