Abstract: The aflatoxin B1（AFB1） chronic poisoning model of ducklings was set up， and one-day-old ducklings were divided into 6 groups. The real-time fluorescence quantitative PCR and western blot were used to investigate the influence of Compound Chai Qin Particles on the mRNA expression and protein expression of CYP3A4， CYP1A2 and CYP2E1 in treated ducks. The mRNA expressions of CYP3A4， CYP1A2 and CYP2E1 of the high-dose， middle-dose， low-dose groups were significantly lower than those of model group in this experiment. The protein expressions of CYP3A4， CYP1A2 and CYP2E1 of the high-dose， middle-dose， low-dose groups were significantly lower than those of model group in experimental 7th to 14th day. And the protein expressions of CYP3A4， CYP1A2 and CYP2E1 of the high-dose groups were significantly lower than those of model group on 21st day. It was concluded that Compound Chai Qin Particles could effectively decrease mRNA expression and protein expression of CYP1A2， CYP2E1 and CYP3A4 in liver microsomes of AFB1 chronic poisoned ducklings. However， with the medication time extended， the mRNA expression and protein expression of CYP1A2， CYP2E1 and CYP3A4 gradually increased.

Key words: cytochrome CYP 1A2, cytochrome CYP 3A4, cytochrome CYP 2E1, Compound Chai Qin Particles, aflatoxin B1, mRNA expression, protein expression