Phytoremediation is a kind of new biotechnology. The plant-based approach to remediation takes advantage of the remarkable ability of plants to concentrate element and compounds from the environment and to metabolize detoxified molecules in their tissues. According to three kinds of phytoremediation,phytostabilization,phytovolatilization and phytoextration,this review concentrates on the mechanisms of phytoremediation,especially the chelation between the hyperaccmulator and heavy metals,and the biosynthesis and genic regulation of the chelatins. Currently phytoremediation is an efficient remediation of heavy metals in the soil,cheap and considerable potential in situ green technology. Phytoremediation has broad application prospects.