Abstract:By using point pattern analysis,we analysed the age structure,spatial distribution patterns and associations of different age-class individuals of four Taxus yunnanensis populations in Lanping County,Northwest Yunnan Province.(1)Forest gap and human disturbance were important factors which influenced age structure of four T.yunnanensis populations.The age structure of population which had a small forest gap indicated stable type and which had a larger forest gap indicated growth types.The age structure of population showed decline type when community structure integrity had no forest gap or population with comparatively larger human disturbance.The decline types were short of individuals of seedling,saplings and small trees and had regeneration difficulties to certain extent.The size of forest gaps is an important factor of population regeneration.(2)Human disturbance,natural environment and its biological characteristics affect spatial distribution patterns of 4 populations.There was a significantly aggregated distribution at overall and every growth stages of population 1.Population 2 and 4 all displayed that aggregated distribution in small scales and randomly distribution in larger scales.Population 3 indicated changes from aggregated distribution to randomly distribution and then converted to aggregate distribution with development of scales.(3)Seedling,small tree and medium tree of population 2 showed aggregate distribution in a small scale and more randomly distribution in a larger scales.Small tree of population 3 showed both aggregated distribution and randomly distribution and medium tree and old tree displayed aggregate distribution in all scales.The degree of aggregation of population 4 reduced gradually with progress of growth stages.(4)Different growth stages of 4 populations showed significantly or close positive correlation.Intraspecific competition is weak which had advantages of population maintain.