In Vietnam, the supervisory biology of water quality has been mentioned many times in the last 10 years. However, in the 2000s, when Nguyen Xuan Quynh and coworkers built the BMWPViet calculation system, the key to identifying macroinvertebrate animals in freshwater (Nguyen Xuan Quynh, 2001, 2004) began to apply the process of supervisory water quality in freshwater water areas of Viet Nam. One problem in relying solely on chemical and physical measurements to evaluate water quality is that they provide data that primarily reflect conditions when the sample is taken. Chemical measurements must be repeated many times because they vary widely in response to short-term fluctuations in water flow and position in the stream. Furthermore, chemical analysis relates only to sampling; organisms integrate effects over a relatively long period and intermittent pulses of pollution that are difficult to detect by chemical analysis. A physical-chemical approach provides a “snapshot” of water quality conditions. In contrast, biological monitoring provides a “moving picture” of past and present conditions and a more spatially and temporally integrated measure of ecosystem health. The study aimed to study the diversity of the aquatic insects and bioindicators of water in the Hai Van area. The result showed that eight orders and 37 families of aquatic insects were found. We are using aquatic insects to estimate the water quality of collected samples in the Hai Van area of Thua Thien Hue province using the BMWPVietcalculation system and ASPT biological index. It shows that the water supply in the researched places can be used for life, industrial branches, agriculture, tourist activities, and entertainment.