In order to increase the efficiency of algicidal bacteria isolation,The components of minimal medium for isolation of algicidal bacteria were tested for the effection growth of Microcystis aeruginosa DS and a modified minimal medium was established..The results indi- cated that glucose at the concentration of 0.1～0.4g/L in minimal medium inhibited the growth of Microcystis aeruginosa DS,and a modi- fied minimal medium was developed using sodium citrate instead of glucose as carbon sourse.On modified medium algicidal bacteria could be succesfully isolated directly from field sample in 1 week. Microcystis aeruginosa DS could grow ewll on modified medium and the algicidal materials were secreted into medium by bacteria and the growth medium could be directly used for algicidal test.