Abstract:A bies yuambaoshanensis is an endangered species endemic to Guangxi in a limited area with less than 900 individuals， and is listed in the Plant Red Data Book of China． Field data were obtained from five 20 m × 30 m plots in Yuanbaoshan Nature Reserve by using tally with contiguous grid quadrat method for time-specific life table，and data from cultured seedlings in nursery, for dynamic life table An obvious periodic fluctuation in size structure of the population was showm． Expecting life ofindividuals larger than 18 cm DBH lowered obviously The survival curve of the population appeared to be a type of Deevey-Ⅲ．The mortality of one-year-old seedlings reached 48％.