Objective: To deeply explore the molecular mechanism of MCLR in the course of MCLR promoting liver tumor. Methods: We applied the two -stage- medium-term theory to set up the animal model, and biochemistry technique to evalu- ate the model, and then, used RT-PCR technique and image analysis to study the mRNA expression of the p53 and p16 in the course of promoting tumor. Results: (1) MCLR could enhance the positive reaction ratio of γ-Glutamyltransferase(GGT). (2) MCLR could increase the mRNA expression of p53, and had not effect on the mRNA expression of p53. Conclusion: (1) MC can promote liver tumor strongly. (2) The expression change of p53 may play an important role in the course of MCLR promoting liver tumor.