Interferon (IFN) is a broad-spectrum antiviral agent, which does not directly kill or inhibit the virus, but mainly inhibits the replication of hepatitis B virus by making the cells produce antiviral protein through the action of cell surface receptors; it also enhances the vitality of natural killer cells (NK cells), macrophages and T-lymphocytes, which leads to the immunomodulatory effect and strengthens antiviral ability. In the mid-1970s it was found that patients with chronic hepatitis B have a low capacity to produce interferon on their own, and after the application of exogenous interferon, it not only produces the above-mentioned antiviral effects, but also increases the density of human leukocyte histocompatibility antigen on the hepatocyte membrane, and promotes the efficacy of T-cells in lysing infected hepatocytes. In adults, after injection of (2-5) X 106 units of interferon, interferon activity in serum begins to be measured at 3 hours, reaches a high level at 6 hours, and essentially disappears at 48 hours. There are many types of interferon available for clinical use. For example, domestic recombinant IFN-1 type and IFN-2 type, imported interferon, Luo perturbation (IFN-2a), Huifuren (lymphoblastoid interferon) and combination of interferon and so on. Various subtypes of interferon; have similar efficacy; interferon; also has a similar effect, but it is easily inactivated in muscle tissue. Interferon preparation into the bloodstream, the stability is poor, the exact efficacy is still under observation, but can be used as a substitute preparation for interferon. Currently, the better dose of interferon subtype preparations in China is (3-5) X106 units/day, and after 1 week of continuous use, it should be changed to every other day or 3 times a week, intramuscular injection, and the course of treatment should be 3-6 months. In the course of interferon treatment of chronic hepatitis B, alanine hydrotransferase (ALT) is commonly elevated at the beginning, and then hepatitis B e antigen turns negative, while ALT decreases and gradually returns to normal, and the general condition improves accordingly. After 3 to 6 months of treatment, about 40% to 50% of patients with chronic hepatitis B can have their hepatitis B e antigen (HBeAg) and hepatitis B virus deoxyribonucleic acid (HBVDNA) turned negative, but only half of them can consolidate the effect of the treatment after stopping the drug. Comprehensive 1991-1996, the national hospitals using IFN; subtypes of chronic hepatitis B patients in the treatment of recent observations of the effect of hepatitis B e antigen conversion rate of 34% to 66%; HBVDNA conversion rate of up to 43% to 80%. It is believed that the disappearance of Hepatitis B surface antigen, Hepatitis B e antigen and Hepatitis B virus deoxyribonucleic acid is easier after using interferon preparation in patients who have been infected with Hepatitis B virus at the level of less than 2 years; the results are better in patients with mild pathological changes in liver biopsy and those who do not have or have a little bit of liver fibrosis; the efficacy of the treatment for the young and strong adults is better than that of the old people; and the near-term effects of the control of the interferon are similar in the comparison between the domestic and imported interferon. More data show that for chronic hepatitis early treatment with interferon preparations for more than six months, and achieve clinical results, is conducive to preventing liver fibrosis, and can block the development of liver cirrhosis. Interferon preparations after treatment, most patients have adverse reactions: initial symptoms of influenza, temporary alopecia, leukocytes and thrombocytopenia, anemia can also occur; high fever, chills, hypotension, nausea, diarrhea, myelopathy and fatigue, etc.; long-term use of more than half a year of interstitial pneumonitis and retinopathy can be seen. However, after stopping the drug, the above adverse reactions and symptoms can disappear. When interferon therapy is applied, if interferon antibodies appear in the early stage, the efficacy of interferon will be weakened accordingly or may lead to ineffective.