Abstract: Paramecium, Euglena viridis and Daphnia magna were separated and purely cultured.Meanwhile, Microcystis aeruginosa were monocultured in batch up to its steady-phase then mixed and cultured together with the above-mentioned three protozoans,respectively.The effects of different concentrations of Microcystis aeruginosa on growths and reproductions of the protozoans were investigatd every day in a regular interval time. The results indicated that Microcystis aeruginosa did not obviously show negative effect...