Abstract: In order to regulate Zhangweixin River better, the ecosystem and health index system of Zhangweixin River is established based on the assessment program outline of health of rivers and lakes issued by Ministry of Water Resources and the in-depth analysis of the influence of natural factors and human activities on Zhangweixin River ecosystem evolution. And a diagnostic model of ecosystem  health of river based on extenics was established and applied in Zhangweixin River. The diagnostic result shows that the ecosystem of Zhangweixin River was in unhealthy state in 2010. The measures including ecological flow operation, water pollution control and water bioremediation are proposed to restore Zhangweixin River.