Acer catalpifolium is a rare and endangered tree species endemic to China, and is the second important protected plant in the country. In order to clarify the structure of A. catalpifolium population and analyze its current survival situation, we selected the typical forest communities in karst forest of Maolan National Natural Reserve located at the junction of Guizhou and Guangxi. Using method of censusing every individual to analyze the population structure and population dynamics of A. catalpifolium we studied the aspects of height, diameter class, static life table, survival curve and life expectancy, providing theoretical basis for the population restoration, and reconstruction of forest ecosystems in degraded karst area. The results showed that: （1） the importance value of A. catalpifolium in the community is low ［valley (0.255), funnel (0.243), hillside (0.188) ］, which is a nondominant species in the Maolan karst forest. (2) A. catalpifolium population distributes in three community types of different topography sites: they are valley forest, funnel forest and hillside forest. A. catalpifolium grows the best with the most amount in valley forest, followed by funnel forest, but the worst and least in hillside forest. (3) A. catalpifolium in different habitats were serious shortage of Ⅰdiameter class (DBH < 2.5 cm，H < 33 cm) individuals, but Ⅱ diameter class (DBH < 2.5cm，H = 33 cm) individuals accounted for a large proportion, the number of middle and large trees were less, characterized by a stable population. (4) In different habitats, the survival numbers of A. catalpifolium population (exceptⅠdiameter class) decreased with the increase of diameter. The curves of mortality (q_x) and killing power (K_x) showed an increasing trend, life expectancy decreased monotonically, and the mortality ofⅠdiameter class in different habitats was negative, indicating a serious shortage of seedlings. The survival curve tended to be the type DeeveyⅡ. As a result, the seedlings of A. catalpifolium have higher mortality during the development process in Maolan karst forest, and the interspecific competition is fierce. In addition, the harshness of the Maolan karst habitat and the lack of soil nutrient space cause the growth of A. catalpifolium to be slow. Therefore, the decline of A. catalpifolium population is related to the harsh karst habitat and human interference.