Sediments is an important sink and sources of pollutants and nut ritive elements, such as heavy metals, organic toxicants, phosphorus, nitrogen, and carbon.In the sediments, organic matter is the key factor to control the environmental behaviors of these substances.In this paper, the studies in the geochemistry behaviors oforganic matter in sediments, and its effects on the behaviors of heavy metals, organic toxicants, phosphorus and carbon in sediments were review ed.The effect of organic matter on the eut rophication of fresh water, ecological tox icology of heavy metals and organic compounds, and the release of greenhouse gas from fresh water were discussed, too.