Rana nigromacuata, Chinemys reveesii , Eriocheir sinensis, Monopterus albus , Misgurnus anguillicaudatus and Procambarus clarkii preying upon Oncomelania hupensis and the mosquito larvae were studied and compared. It showed that all can feed Oncomelania hupensis , and mosquito larvae in varying degrees. On Oncomelania hupensis , the sequence of feeding quantity is Procambara clarkii > Eriocheir sinensis > Chinemys reevesii > Rana nigromacuata; and on Culex , that is Chinemys reevesii > Procambarus clarkii > Rana nigromacuata > Eriocheir sinensis. In the epidemic region, the outdoor test demonstrated that Oncomelania hupensis is much less in the pools in which with Eriocheir sinensis and Procambarus clarkii respectively than the controls. It has been concluded that four ecological economic models have been formed to purify the epidemic water. Based on the experiments as well as the relavant studies for eight years, four bio-economic models for purifying epidemic sources in farming waters are given in detail. They are: 1) taro, frog, ricef ield eel, loach, earthworm, vegetable polyculture model; 2) lotus, vegetable, tortoise, ricefield eel, loach polyculture model; 3) lotus, Chinese mitten crab, loach polyculture model; 4) reed, crayf ish, loach po lyculture model. The application and benef it for all models are also given in the paper.