Abstract:Dissolved inorganic nitrogen, dissolved inorganic phosphorous, total nitrogen, total phosphorus,conductivity, pH, dissolved oxygen and chlorophyll-a were monitored in 46 sections along the Taizihe River, Liaohe River Catchment to understand their spatial distributions. The relationships between dissolved inorganic nitrogen, dissolved inorganic phosphorous and chlorophyll-a concentration were identified using the regression analysis. The relationship between water quality and environmental influencing factors was identified using redundancy analysis.The results showed that distributions of nitrogen, phosphorous and chlorophyll-a concentration had a certain spatial-related variability.The concentration of nitrogen, phosphorous and chlorophyll-a were low and stable in the upstreams, and were increasing and fluctuating in reaches of Liaoyang. In the reaches of Anshan the concentrations were the highest. Redundancy analysis showed that the spatial distribution characteristics of N and P were closely related to the land use, altitude,width of the riparian buffer and vegetation diversity. Ammonia nitrogen, nitrate nitrogen, dissolved inorganic nitrogen, dissolved inorganic phosphorous,total nitrogen, total phosphorus, and conductivity were positively correlated with chlorophyll-a concentration. It indicated that nitrogen and phosphorous could promote the growth of alga. Eutrophication evaluation index in Taizihe River Basin showed that there were 27 sample sites in the mesotrophic level,19 sample sites in a status of eutrophication, no oligotrophic, hyper eutrophic and extremely eutrophic status.