Pilot test was made for the removal of nutrients in eutrophic source water through the use of enriched mi- crobes by artificial medium.The results indicated that the nutrient elements removal efficiency enhanced as the me- dium density and hydraulic retention time(HRT)increased.The removal rates of total nitrogen(TN),total phos- phorus(TP),ammoniacal nitrogen,nitrite nitrogen were 26.6%,72.1%,43.2% and 79.4% respectively under the medium density of 26.8% and HRT of 5d.It is evident that enriched microbes on the artificial medium can ef- fectively remove the nutrient elements in the eutrophic source water.Because of increasing the water velocity,the detimination phenomena of the dissolved oxygen(DO)is lowered and oxidation-reduction potential(ORP)is elim- inated.The removal ratio of ammonia nitrogen,nitrite nitrogen was enhanced slightly whereas the elimination effect of TP,phosphate,dissolved total nitrogen(DTN)did not.So the sedimentation isn't the main approach of nutri- ent elements removal in source water.The large quantity of microbes is enriched on the surface of artificial medi- um.The nitrification and denitrification is one of the main mechanisms for water quality improvement in eutrophic water.