Disclosed is a use of C15-substituted andrographolide derivatives in preparation of anti-hepatitis B virus medicaments. In the present invention, the HepG2.2.15 cells are used to measure the amount of the hepatitis B virus surface antigen (HBsAg) secretion in the supernatant of the culture; the duck hepatitis B virus (DHBV) is used to infect the model and the DHBV-DNA level in serum is measured, and the pathological change in hepatic tissue is observed. A number of andrographolide derivative compounds are screened, compounds having a good anti-HBV effect are preferred, which has a structure represented by general formula 1 set forth herein. Due to high anti-HBV activity and low toxicity, as well as good protection against hepatic injury, the compounds can be used as the active ingredient for preparing anti-HBV medicaments, thereby providing a new pharmaceutical way for treatment of hepatitis, and broadening the range of clinical medicines.