Abstract: Rhodiola fastigiata is an endangered Tibetan medicinal plant,which is regarded as a plant of the second-class protection in our country.Based on investigation data of plots and quadrats,the paper analyzed the age structure of R.fastigiata population,compiled the static life table,drew mortality curve,killing power curve,survival curve,and survival function curve.The population quantitative dynamics was predicted by the time sequence prediction model.Results showed that the age structure of R.fastigiata population was presented as the typical pyramid shape.The two dynamic indexes of V_piand V^<sub>piof the population quantity were 33.89% and 1.69 %(both more than zero),respectively,which showed the population was steadily increasing.The survival number of every age class was decreasing with the increasing age class.The mortality rate of age class Ⅱand Ⅴ were relatively high(reached 90.29%),and the average mortality rate accounted for 29.96%.The survival curve of R.fastigiata population approached the B₃ subtype of Deevey-Ⅱ.With the changing age class,the mortality rate had a similar change trend to the killing power,and they were both M shape curves.The survival functional curve for R.fastigiata population indicated that the population was characterized by reduction in the early age period(before age class Ⅳ),stableness in middle age period(Ⅳ-Ⅵ age class),and recession in late age period(after age classⅥ)because of physiological exhaustion.The young individuals would be relatively abundant,and the population would show a trend of steady growth in the upcoming Ⅱ,Ⅴ and Ⅷ age classes.We suggested some things to be done were as follows to protect R.fastigiata,protecting and improving primitive habitat conditions,developing proper artificial seeding,building reproduction base and gene bank,implementing ex-situ conservation,strengthening monitoring of diseases and insect pests.

Key words: Rhodiola fastigiata, static life table, dynamic index, protection method, Sejila Mountains