Immunomodulators are subdivided into immune enhancers, immunosuppressants and immunomodulators. Commonly used immunomodulators include interferon, transfer factor, immune ribonucleic acid and thymosin. 1. Transfer factor: it is a kind of drug that enhances the immune function of human body, and can enhance the immune function of human cells. Immune ribonucleic acid: it is the genetic material of immune information produced by lymphocytes and macrophages after being stimulated by specific antigens. 2. Thymic hormone: regulates and controls the differentiation and maturation of T cells and the expression of their functions. 3. Interferon: mainly through the cell surface receptors to make cells produce antiviral proteins, thereby inhibiting the replication of hepatitis B virus, play an immunomodulatory role, and enhance the ability of antiviral. According to the patient’s condition, the doctor can determine which kind of immunomodulator to use.