Over the past few years, there are many activities had negative impacts on the surface water of the Dong Nai river such as industry, agriculture, and service development activities; therefore river water quality is significantly relieved. This study was conducted to evaluate the effect of elements on the water quality in 2022 through analyze the parameters of pH, temperature, DO, BOD5, COD, N-NH4+, P-PO43-, TSS, turbidity, total Coliform on 54 samples, compared with QCVN 2015 for river water quality and the water quality index calculation WQI. The analysis results show that the water quality of Dong Nai river, sections flowing through Bien Hoa city from Jan to Dec is not quite good, most parameters reach the limit value B1 according to QCVN 08:2015/BTNMT; however, the values of parameters DO, total coliforms, TSS exceed the limit value B1 significantly. WQI values fluctuate at a fairly high level from 17 to 68, and the average WQI of the river reaches is quite low, so the authority should have promulgated the law to protect the water surface of this river; therefore water quality assessment is significant for better control and management of the surface water environment in Vietnam.