Abstract: Since 1970s,microcosm has been received an increasing attention as an effective tool for assessing the environmental impact of chemical pollutants. The application cf aquatic microcosm to environmental research developed rapidly because the released chemicals from point/non-point sources would enter aquatic echosystem through direct and indirect ways. During the earlier pericd,the particular emphasis was laid on the fate of chemicals in aquatic environment. Since the later 1970s,the attention has been gradually focused on the ecological effects of toxic substances at various biological organization levels within aquatic ecosystems. This paper gave a review in following four aspects: 1) some concepts concerning microcosm; 2) various types ef aquatic microcosm used in environmental research; 3) some disputed problems; and 4) a new trend in the use of aquatic microcosm technique and its prospects for the future.

Key words: Aquatic microcosm, Multispecies toxicity, Fate of chemicals, Hazard assessment of chemicals