Abstract:According to the biological assessment, the eco-healthy status is very poor at present. The eco-healthy stressors were identified for the Qingyang Reach of Dagujia River in order to provide scientific guidance for restoration of eco-health of the Qingyang reach. The related data or information was obtained by literature review and field investigation. The identifying method, consisting of listing the candidate causes, eliminating the lternatives and enhancing evidence analysis, was used in order to retrieve the key stressors. Results showed that the biological impairment of the Qingyang reach was mostly probably caused by nutrient enrichment due to total ammonia nitrogen increase, loss of optimal habitat because of runoff changes and algae moderate growth induced by nutrient enrichment and runoff change. The secondary stressors of biological impairment of this reach was the algae moderate growth and sediment increase resulting from TSS increase. The main measures for eco-health restoration of Qingyang reach includes controlling streamflows through the river and the dams and making them approach to natural processes, and reducing the concentrations of NH3-N and TSS in rivers by pretreatment of sewage before discharging into river. In the future, it is necessary to develop the quantifying techniques about the identification of stressors in order to reinforce the objectivity and accuracy of identification process.