Water quality deterioration in rivers has become a serious environmental problem. It is of great significance for management to carry out comprehensive assessments of water quality. Due to different objectives, it is crucial to select reasonable evaluation criteria for a comprehensive assessment. In this study, we assessed the water quality conditions by the Water Health Assessment Index, based on the expectation and threshold value (ETI) and water quality index (WQI) in Yixun River, which is the water source for the "Water Diversion Project from Luanhe River to Tianjin City". The results showed that 1) the water quality rated at a "good" level for ETI, and "moderate" level for WQI; 2) the water quality in 24 sites was classed into four levels for ETI and only two levels for WQI; 3) the water quality decreased significantly from upstream to downstream in Yixun River. Especially for ETI, the water quality changed from "excellent" to "poor". 5) The two indices, ETI and WQI, showed a significant correlation (R=0.951, P < 0.01). From the results of the stepwise multiple regression, the dominant factors for ETI were DO, EC, SS, BOD₅, and TP (P < 0.05); and those for WQI were DO, SS, BOD₅, TP, TN, and NH₃-N (P < 0.05). These results suggested that 1) the water quality deterioration in Yixun River was closely related to the land use. 2) For aquatic environment management, ETI, as an assessment based on the relative state of water quality, could reflect spatial variation in river water quality better than WQI, which was more suitable for water quality management in a basin. Therefore, ETI can help managers to make and set management objectives for polluted rivers or streams based on the water quality, and can be used as an effective method to evaluate river management performance. Meanwhile, WQI, as a method for evaluating the absolute state of water quality, is more suitable for evaluating the temporal variation in river water quality, and plays an important role in evaluating the effect of aquatic environment management.