Many countries have used the biodiversity indexes to monitor environmental quality as well as assess ecosystem impacts, but most provinces and cities in Vietnam carrying out water monitor through physicochemical sampling that cause of costly. In this study, zoobenthos were collected from the rivers’ bottoms, where received wastewater from domestic activities (3 points) and from industrial productions (3 points) in Can Tho city. At domestic wastewater effected sampling points, there are 29 species belonging to 6 classes including Oligochaeta, Polychaeta, Bivalvia, Gastropoda, Crustacea and Insecta; the species density of 1,930 and 7,700 individuals/m2 in December and March. The industrial wastewater effected sampling points recorded 17 species belonging to 5 classes including Oligochaeta, Polychaeta, Bivalvia, Gastropoda, and Insecta; the species density during December and March are 3,890 and 5,680 individuals/m2. For the diversity index, the H’, DM, d, and ASPT values show better environmental quality received domestic wastewater than that of industrial wastewater. The biological index derived from benthic assessment could applied for environmental quality monitoring program at studied sites.