Abstract: Dissolved organic matter (DOM) is an important and active component in both terrestrial and aquatic ecosystems,while soil DOM plays an important role in the pedogenesis,mineral weathering,and translocation of pollutants in soils.It has become a hotspot in environment science,soil science and ecology.Soil DOM has important effects on the chemical and biological behaviors of heavy metals in soil-plant system,but its mechanism is not identified.The study on soil DOM in China was still in its initial stages,and most studies only reported that the activity of heavy metals in soils was affected by the DOM produced from organic fertilizer.This review is to summarize the recent literatures regarding the formation of soil DOM and its affecting factors,and the effect of soil DOM on the chemical and biological behaviors of heavy metals in soils.The main affecting mechanisms of soil DOM on behaviors of soil heavy metals were summarized as complexing with heavy metals,competing with metals for adsorption sites,and affecting soil pH value.

Key words: Dissolved Organic Matter (DOM), Soil, Heavy metal, Bioavailability