The objective of this study is to apply the WQI index to assess the quality of Luy river surface water flows through Binh Thuan province and propose solutions to improve surface water quality in accordance with the society economic development Binh Thuan. Quality of Luy river water most of the parameters in the upstream areas reach A2 column; QCVN 08-MT: 2015/BTNMT, except BOD5 and COD exceeding - times, while downstream only meets the level of B1 column. WQI values have large fluctuations in space and time, WQI in monitoring positions from 53 to 91 (June, 2018). | Method of calculation application of WQI index to assess the status water quality and proposal of management Luy river Binh Thuan province