Abstract: Being a branch of environmental biology, pollution ecology is a subject of studying the regular pattern of organisms and their polluted environment. Water flea has been widely used in the field of ecotoxicology due to its short growth cycle, small size and sensitive to pollutants. Water flea has also been proved to be potentially useful in genetic development, autoimmune diseases, and the structure and function of biological macromolecules. The status of using water flea as a biological indicator in the field of ecotoxicology based on the evaluation index such as reproductive toxicity, feeding rate, growth rate, behavior change and antioxidant enzyme activities was introduced briefly in this review. The purpose of this paper is to offer reference data for further research in ecotoxicology and other biological field.