Abstract: In recent years，more and more attention has been paid to treatment of heavy metal contaminated soil.Physical and chemical properties of soil has an important impact on morphology and bioavailability of heavy metals in soil.Effects of physical and chemical properties such as soil pH，redox potential，organic matter content and different clay minerals on speciation of heavy metals in soil were analyzed and discussed.Mechanism of change of speciation of heavy metals in soil caused by different factors was summarized.Transformation of heavy metals from bioavailable state to stable state in soil was put forward，which provided guidance for reducing heavy metal pollution in soil.