Abstract: Heavy metal pollution in water and soil has seriously affected the quality of the environment, and caused a lot of food safety problems. Plant, as a creature, is most closely related to water and soil. The phytoavailability of heave metal has been a research hotspot of ecological environment and food security early warning.The diffusive gradients in thin-films ( DGT) technique, a new in- situ passive sampling technique, is recognized as one of the most promising techniques to assess heavy metal phytoavailability.In this paper, the basic principle of measuring heavy metal speciation by DGT was stated.The predictions of heavy metal phytoavailability by DGT were focused.The prospects of predicting heavy metal phytoavailability by DGT were also evaluated.