Abstract: Introduces the concept of bioavailability，analyses the influence factors to bioavailability of heavy metal in soil，makes certain that the true and real absorption of the heavy metal elements in soil by creatures is the effective criterion of heavy metals pollution. Based on viewing domestic and foreign literature，bioavailability of lead and mercury in soil are summarized. Furthermore，problems and future trends of bioavailability research of heavy metal are discussed in detail，to provide reference for researches.

Key words: heavy metal, lead；mercury, soil pollution, bioavailability