Abstract: In recent years,the increasing intensity of human activities and the increase of regional developing items led to a sharp decrease of natural distributed area and natural population number of rare and endangered species Davidia involucrata, and now, its natural distributed population is on the point of extinction.This paper analyzed the geographic distribution situation of Davidia involucrata in different geologic and historical periods,and discussed the major reasons for forming the geographic distribution and dynamic changes of population.Through many field investigations and references,some protecting measures were presented.

Key words: Davidia involucrata, Population, Population density, Proteting measures