Abstract: In the late 1950s, the Brassaiopsis angustifolia had been collected and the new species had been identified. So far no other B.angustifolia have been collected and there are no other academic literatures about it. B.angustifolia had been re-discovered recent years. The morphologies, the living habits, the communities and the population biology were investigated. Results showed that B.angustifolia was sporadically distributed in the mid-mountain moist broad-leaved forests with the altitude of 2 100 to 2 250 m in the Yuanjiang. The leaves of B.angustifolia were single leaves, but not the described ′Leaves palmately′ in Flora of Yunnan province. Several characteristics of B.angustifolia, such as inflorescence dormancy and cauliflory, was very special in genus Brassaiopsis and Araliaceae family, and even in the whole Plant kingdom. B.angustifolia distributed only in one place in gancha Village in Yuanjiang county and the distributive area was small, the plants number of species was about 152 and it has been listed into IUCN endangered (EN) species and also an extremely small population species.