Abstract: Seed germination and haustorium formation stimulated by fluridone were observed in three Cistanche species. The seeds treated by fluridone began to germinate after 10 days, and then the apex of the seedling radicle swelled and haustorium developed. The percentage seed germination of C. tubulosa in all three species peaked at 82%, and the percentage haustorium formation of C. sala peaked at 52%. The seeds treated by distilled water did not germinate and develop haustorium. These results indicate that fluridone is the signal substance for seed germination and haustorium formation in Cistanche species.