The aquarium simulation method was used to explore the influence of feed residue on the ecological factors of different aquaculture waters.The waters which have cultured the grass carp,tilapia and snakehead without feed residue were named as C1,C2 and C3 group while the waters with feed residue were marked as T1,T2 and T3 group.The experiment lasted 15 days. The results indicated that the dissolved oxygen content was positively correlated with pH value in C1,C2 and C3 group(P＜0.01) .At the end of the experiment，the densities of phytoplankton and the diversity indexes of C1,C2 and C3 group were increased by 43.50%,36.12%,27.57% and 5.76%,8.01%,5.63% respectively compared with those at the beginning of the experiment,and the water environment tended to be stable.The amount of culturable bacteria of T1，T2 and T3 group was negatively correlated with dissolved oxygen content and pH(P＜0.01) ,and positively(P＜0.01) correlated with total phosphorus,ammonia nitrogen and nitrate content in the water.At the end of the experiment,the densities of phytoplankton of T1,T2 and T3 group were 11.54 times,9.57 times and 8. 68 times as much as those at the beginning of the experiment,and the diversity indexes were decreased by 18.11%,12.71% and 4.35%.Microcystis in T1 and T2 group,while Synedra in T3 group had become the dominant population at the end of the experiment.The increased tendency of the densities and diversity indexes of phytoplankton in C1,C2 and C3 group indicated that the water without feed residue tended to be stable during the experiment.The phytoplankton densities of T1，T2 and T3 group increased while the diversity indexes of these groups decreased,which indicated that the water environment tended to be eutrophic.The variation trend of different aquaculture waters may be closely related to the difference of microbes,and the variance of phytoplankton composition in the water may be related to the change of pH value in the waters．