Provided are use of a saponin compound of formula (I) or (II), or a pharmaceutically acceptable salt, prodrug or solvate thereof, in the manufacture of a medicament targeting PD-1. The medicament targeting PD-1 is one which treats a disease by inhibiting PD-1 from binding to a ligand thereof. The disease may be a tumor, an infection caused by a bacterium, a virus or a fungus, or an inflammatory disease.
