Abstract：This study examined several metabolic detoxification indexes (AHH, GST, GSH and SOD) and the change of DNA damage in the Philippines clam (Ruditapes philippinarum) gill filament and digestive blind sac exposed to different concentrations of PAHs. The concentration of B[a]P was set to be 0, 0.01, and 0.2 ug/L. The results showed that B[a]P had a significant induction effect on the AHH, GST, GSH and SOD activity of gills and digestive blind sacs of R. philippinarum (P<0.05), and showed obvious characteristics of time and dose effect. All the indicators of branchial filaments and digestive blind sacs had similar change rules. During the exposure experiment, AHH activity was induced to increase, and the degree of induction was positively correlated with the concentration of violent pollution. GST and GSH activity were firstly induced to increase, then inhibited and correlated with B[a]P concentration. The activity of SOD showed a certain peak change, reaching the maximum in 3 days, and then was inhibited. The level of DNA single chain fracture was also significantly induced, and the degree of induction was positively correlated with the pollution concentration. Exposure to PAHs affected the AHH, GST, GSH and SOD activity in the R. philippinarum gill filaments and digestive blind sac, and then reflected the ability of the body's metabolism and detoxification, while the DNA level of single fracture directly reflected the oxidative damage degree of the body. Both of these constitute a combination of biological markers, can accurately reflect the toxicological effect of PAHs to the R. philippinarum.