The study on concentrated shrimp farming activity ip Hai Dong, Hai Hau district, Nam Dinh province indicates that this activity does not only have a significant impact on the local economy but also adversely affect to water environment quality. More than 40 percent of people's income in Hai Dong is from vannamei shrimp farming activity. However, the rapid and uncontrolled development of shrimp ponds had great influences on the quality of the living environment of local people. The quality of water in shrimp ponds, canals receiving water from shrimp ponds has been polluted. In the shrimp ponds, concentration of TSS exceed acceptable standards 295.2 times, level of COD exceeds acceptable standards 75.25 times, level of NH4 + exceeds acceptable standards 62.5 times. The quality of sewage from shrimp ponds also has been polluted organic. TSS levels exceed acceptable standards 20.77 times, concentration of COD exceeded the acceptable standard 8.73 times, level of BOD exceeds acceptable standards 7.88 times, level of NH4- exceeds acceptable standards 58.8 times.