We studied antitrichomoniasis with the extract of Gentiana scabra val buergeri, which may be effective in treating infectious diseases. The growth inhibition against T. vaginalis became optimal when tile extract concentration was 0.7 mg/ml and the cells were seeded at a density of 3$ imes$10$^5$ per well. After incubation for 12, 24, 36, and 48 hrs, respectively, the number of cells were each 5$ imes$10$^5$, 1$ imes$10$^5$, 1$ imes$10$^5$, and none, respectively. Under the electron microscope, the experimental group showed that the nucleus, karyosomes, and chromatin were weaker than those in the control group. After incubating for 3 hrs, the cells were destroyed completely, and only a remnant remained. The hydrogenosomes disappeared almost. The vacuoles and autophagic vacuoles increased. The cells became regressive form.