Abstract: In this study,marine bivalve molluscs species,Sinonovacula constricta,were exposed to benzoapyrene(BaP)and phenanthrene(PHE)due to their ubiquitousness and bioavailability in the marine aquatic environment.Kinetic parameters(uptake rate constant(k₁),elimination rate constant(k₂),accumulation factor(BCF),and biological half-life(B_1/2))of the BaP and PHE bioaccumulation and depuration were calculated by two-compartment kinetic model for 15-day uptake and subsequent 9-day depuration periods.The results showed that the bioaccumulation ability of BaP was higher than PHE in S.constricta during 15-day uptake period.The increase of BaP was 0.45 ng/(kg·d)(40 μg/L groups),0.33 ng/(kg·d)(20 μg/L groups),0.23 ng/(kg·d)(10 μg/L groups),respectively.The increase of PHE was 0.33 ng/(kg·d)(30 μg/L groups),0.25 ng/(kg·d)(20 μg/L groups),0.18 ng(kg·d)(10 μg/L groups),respectively.The uptake and depuration periods of BaP and PHE were mainly in the initial stage of experiment.Those values of k₁ of BaP and PHE were calculated as varying from 0.39 to 0.52 and from 0.30 to 0.43,meanwhile,the average values of k₁ were 0.44 and 0.36,respectively.Those values of k₁ decreased with the increase of BaP and PHE exposure concentration in ambient seawater.Those values of k₂ of BaP and PHE were calculated as varying from 0.001 6 to 0.001 7 and from 0.002 8 to 0.003 3,meanwhile,the average values of k₂ were 0.001 6 and 0.003 0,respectively.There was no obvious variation trend of those values of k₂.Those values of C_Amax of BaP and PHE were calculated as varying from 3 062.76 to 9 758.25 μg/kg and from 1 308.54 to 3 171.84 μg/kg,meanwhile,the average values of C_Amax were 5 969.08 and 2 287.71 μg/kg,respectively.Those values of B_1/2 of BaP and PHE were calculated as varying from 407.73 to 433.22 d and from 210.68 to 248.06 d,meanwhile,the average values of B_1/2 were 421.20 d and 232.04 d,respectively.Those values of C_Amax and B_1/2 increased with the increase of BaP and PHE exposure concentration in ambient seawater.