Abstract:Aspects of the reproductive biology of Cimicifuga nanchuanensis Hsiao have been studied to shed light on the endangerment of this species, endemic to Jingfo Mountain in Sichuan Province of China. The only one population of C. nanchuanensis includes 6 000 ~ 8 000 individuals, in which adult blooming plants accoum for 19%. Inflorescence is panicle,flowering period lasts from mid August to early October and fruits ripe in mid or late November. C. nanchuanensis is dichogamous and the stigmas mature 7 days after withering of flower. In natural conditions the rate of seed-setting is 5.8% ~ 7.0% in average. However, hand pollination can raise the rate greatly to 28.0%. Endosperm type is nuclear and embryos are just at the globular stage when seeds shed from their maternal plants. Pollen limitation is one of the reasons for this species endangerment.