Abstract: The biotope and population structure of Cycas parvulus in Lishejiang watershed of Dinosaur River Nature Reserve Area in Yunnan Province was surveyed The results showed that 925% of the C parvulus plants grew on the shady bank of Lishe River under the deciduous seasonal forest at an elevation between 1100m and 1400m The population density of C parvulus was about 11 plants per 100m2 The age structure of C parvulus population showed to be in pyramid shape, in which the proportion of Ⅱage class was the largest, accounting for 3294% of the total Resulting from human disturbance, the number of the plants older than Ⅳ age class only counted for 2157% of the total At present, the C parvulus population is mainly endangered by human gathering and biotope destruction It was proposed to reinforce conservation measures in order to protect the C parvulus resource scientifically and rationally