Abstract: Kinetic parameters were evaluated for biological accumulation and release of two heavy metals Pb and Cd in gill,hepatopancreas,muscle and haemolymph of Eriocheir sinensis by using two-compartment bioconcentration model to carry out the experiment in which the crabs were exposed to the water environment with Pb concentration of 0.25mg/L,0.50 mg/L,0.75 mg/L,and Cd concentration of 0.025 mg/L,0.050 mg/L,0.075 mg/L.Heavy metal uptake rate constant (k1),extracting rate constant (k2),bioconcentration factor (BCF) and biological half-lives (B1 / 2),equilibrium concentration of heavy metals in vivo CAmax were obtained by non-linear curve fitting.The results showed:1.Obvious concentration of Pb and Cd was found in Eriocheir sinensis and the concentration of heavy metals in crab gill,hepatopancreas,muscle exhibited an apparent positive correlation to accumulation time as well as the exposure concentration of heavy metals,but haemolymph in the enrichment phase went in a haphard way.Accoding to the model,the maximal metal contents in gill,hepatopancreas and muscle (CAmax) were positively correlated to the exposure concentration.2.Pb and Cd were accumulated selectively in the major organs and tissues in Eriocheir sinensis.Before this experiment,Pb distributed in Eriocheir sinensis as follows: hepatopancreas > gills > muscle > hemolymph and Cd: gills > hepatopancreas > muscle > hemolymph.After exposure to the water in different environments,Pb distribution was shifted: gills> hepatopancreas > muscle> hemolymph; and Cd: hepatopancreas > gills > muscle > hemolymph.3.The accumulation and release of Pb and Cd were both slow in organs and tissues of Eriocheir sinensis.After 16 days’ exposure,the concentration of Pb and Cd didn’t reach a steady state.The bioconcentration factor (BCF) of Pb and Cd in the tissues and organs ranged from 5 to 51 and 6 to 3148 respectively,indicating that the absorption of Cd was much more than that of Pb in Eriocheir sinensis.The biological half-lives of Pb and Cd in the tissues and organs (B1/2) ranged from 4 to 9d and 8 to 57 d,which signified that the release of Cd is significantly slower than that of Pb.