Abstract: Objective: The effect of serum ferritin levels on interferon treatment with the core promotor gene mutants in chronic hepatitis B was observed in this study.Methods: The core promotor gene mutants with chronic hepatitis B were detected by using mismatch-PCR restriction fragment length polymorphism assay and the levels of serum ferritin with interferon treatment was also observed in this study.Results: It was showed that following the exaggeration of disease, the serum ferritin levels were raised and obviously decreased the effect of interferon therapy (P <0.05) when SF≥300 ng/ml. The serum ferritin levels in the mutant type group were significantly higher than that in the wild type group (P <0.001) in the route of interferon treatment. Conclusion: The results indicate that the level of serum ferritin has close relationships with the severity of liver diseases, height level of serum ferritin can decrease the effect of interferon treatment, and it can promote the levels of serum ferritin in these patients with the core promotor gene mutants.