Abstract:Cymbidium tortisepalum is an endangered orchid distributed in northwestern Yunnan, southeastern Sichuan, and Taiwan.In the present paper, the pattern of morphological variation and the mechanism of variation formation and maintenance in C.tortisepalum were examined.Investigations on the morphological characters of C.tortisepalum revealed that 77.84% of total morphological variation was found within populations.This research improved current data on and understanding of the taxonomy, cultivation, and resource conservation of C.tortisepalum.