Abstract: Based on line transect survey and data statistics, the population structure and dynamic characteristics of Alsophila spinulosa population in the tropical rainforest of Daoluo mountainshan of Hainan province are studied by static life tables, survival curves and time series prediction on the basis of individual and main stem grading. The current situation and future development trend of the population are analyzed. Results indicate that the age structure of Alsophila spinulosa populations in the study area is pyramidal, but there are variousin the each line transect due to environmental differences. The static life table show that Alsophila spinulosa population has a high mortality and disappearance rate in the age class Ⅰ. The survival curves of the upstream and midstream populations are Deevey Ⅲ, while the downstream is Deevey Ⅱ. The quantitative index of population dynamics indices also indicated that Alsophila spinulosa in the study area is a growing population, but it is highly sensitive to external disturbances. Time series predictions show that the population size of each age class increased in future. The population of Alsophila spinulosa in the study area have the ability for natural regeneration, and maintaining the current community structure and habitat is conducive to the reproduction of the populations.