To investigate the mechanism of moxibustion in regulating cellular apoptosis in rat's precancerous lesion of primary hepatocellular carcinoma (HCC). Methods:Seventy-four rats were randomly allocated to normal group,model group and moxibustion group,and the diethylic nitrosamine (DEN) was used to establish HCC model. Moxibustion with moxa cone which is as big as a grain of wheat was performed on acupoint Zusanli (ST 36),3 cones for each acupoint and 0.5 mg for each cone,the treatment was given once a day,totally 16 weeks. Then the changes in the body weight,liver weight and thymus weight,a morphological change in the liver tissue and changes in γ-GT and GST were observed;Immunohistochemical staining method was adopted to observe the tendency of changes in relevant apoptosis genes such as C-myc,N-ras and mutant type P53,and the influence of moxibustion on cell cycle modulation genes such as cyclinD1,CDK4 and p16. Results:Moxibustion could reduce the activities of γ-GT and GST in the blood,obviously decrease the protein expression of relevant apoptosis genes such as C-myc,N-ras and mutant type P53 and markedly inhibit the over-expression of relevant cell cycle modulation genes such as cyclinD1 and CDK4 and the mutation of cell cycle modulation gene p16. Conclusion:Moxibustion might play a certain role in relieving HCC precancerous lesion and its action mechanism might be related to the regulation on partial apoptosis genes.