This paper arranged and analyzed the monitoring data of water quality of 13 sections from January to April in 2010 in Xi'an Chan-ba River in order to investigate the situation of water pollution.The main monitoring factors are COD,NH3-N and BOD.The water quality in lower reach of Chan-Ba River was evaluated in detail.The results showed that water quality is satisfied with the corresponding water quality standard above the sections of Xianning Bridge,according to country's current environment quality standar...