Disclosed are a sesquiterpene derivative and a use of the same in preparation of a medicament for treating hepatitis B diseases. The sesquiterpene derivative has the effects of down-regulating the hepatocyte nuclear factor 4α (HNF-4α) and significantly inhibiting the hepatitis B virus, and can be used for preventing and/or treating and/or assisting in the treatment of liver system diseases and symptoms caused by the hepatitis B virus, and can be used as a hepatic protective agent. In addition, the synthetic sesquiterpene derivative can also be used for preventing or treating viral infectious diseases and conditions resulting from the influenza virus, coxsackievirus, herpes simplex virus, etc. Also involved is the preparation of the synthetic sesquiterpene derivative, which acts as a raw material, in clinically acceptable pharmaceutical formulations, such as oral dosage forms such as tablets, capsules and drop pills or non-oral dosage forms such as inhalants and injections.