Abstract: ObjectiveThe present study was conducted to investigate the effects of three kinds of Chinese herbal medicine viz., Astragalus membranaceus, Bupleurum chinensis and Coptis chinensis on praziquantel(PZQ) metabolism and CYP1A1 & CYP3A activities of Carassius auratus, in order to understand interactive mechanism of traditional Chinese herbal combined with western medicine, further lay foundation for optimize safety administration system of aquatic product.MethodThe crucian carps were divided into 8 groups, blank control group(A0) and PZQ control group(A1) were fed on basic feed without Chinese herbal; groups A2-A4 and B2-B4 were fed on feed with A. membranaceus, B. chinensis and C. chinensis for 30 days, respectively. Then, the caudal vein blood samples were collected from groups A2-A4 at 0.25, 0.5, 1, 3, 6, 12, 24, 48 and 96 h after oral administration of 10 mg/kg PZQ, and PZQ concentrations of samples were simul-taneously detected using high performance liquid chromatography(HPLC). Meanwhile, activites of CYP1A1 and CYP3A in liver were determined at 3 h after oral administration of 10 mg/kg PZQ from groups A0-A4 and B2-B4. ResultPZQ con-centrations of blood first increased and then decreased in groups A1-A4. The time to peak (Tmax) of PZQ in blood of C. au-ratus in groups A1, A2, A3 was 1 h, and PZQ peak concentrations(Cmax) was 2.71, 2.90 and 3.01 mg/L, respectively. But Tmax of PZQ in blood of C. auratus in group A4 was 3 h, and Cmax was 2.50 mg/L. In addition, the elimination half-life(t1/2β) and area under the curve(AUC(0-∞)) of groups A2-A4 were higher than control group(A1), total clearance rates(CL/F) of groups A2-A4 were lower than that of group A1. PZQ could significantly improve CYP1A1 and CYP3A activities in liver of C. auratus(P<0.05, the same below), however, the three kinds of Chinese herbal medicines(A. membranaceus, B. chi-nensis and C. chinensis) could inhibited CYP1A1 and CYP3A activities from increasing. ConclusionA. membranaceus, B. chinensis and C. chinensis can improve the bioavailability of PZQ, but also greatly slow PZQ metabolism, resulting in PZQ remaining in body of C. cauratus for longer time. So, compatibility of Chinese herbal medicine and PZQ should be considered seriously in aquaculture.