Interferons (IFNs) have antiviral, antiproliferative and immunomodulatory effects.IFN-α and IFN-β have predominantly antiviral effects; whereas IFN-γ has a more pronounced immunomodulatory effect but weaker antiviral activity. In most countries, IFN-α is the most widely studied and only IFN approved for the treatment of hepatitis B. Although generic IFNs were initially used, they have generally been replaced by pegylated interferon (PegIFN). PegIFN-alpha and IFN-alpha have been approved for the treatment of hepatitis B in China. The common side effects of interferon are flu-like symptoms, blood cell suppression, abnormal thyroid function, etc. Therefore, during the period of interferon, in addition to routine rechecking of liver function, hepatitis B DNA, liver ultrasound, we should also add blood routine and thyroid function.