Abstract: The liver is closely related to the thyroid function.On one hand,many liver diseases can cause abnormal thyroid function,such as hepatitis B virus (HBV) infection,hepatitis C virus (HCV) infection,liver cirrhosis,and nonalcoholic fatty liver disease.Thyroid dysfunction is also commonly caused by interferon alpha treatment for anti-HBV or HCV therapy.On the other hand,thyroid diseases such as hyperthyroidism or hypothyroidism can result in abnormal liver function.In addition,liver injury can also be frequently caused by antithyroid drugs or levothyroxine of over conventional doses.The causal relationship between abnormal liver function and thyroid dysfunction remains unclear.