Abstract: Based on investigation on the communities,three dominant species at three succession stages of karst forest in Maolan National Nature Reserve were selected as the object of research through the calculation of important values.The dynamic characteristics of age structure,life table and survival curve of Clausena dunniana,Acercinn amomifolium and Mallotus repandus were studied.The results showed that the change of diameter at breast height frequency of Mallotus repandus was L pattern-interval pattern-L pattern from succession early stage to later stage and the population was growth form;The change of diameter at breast height frequency of Acercinn amomifolium was all L pattern and the population was growth form;The change of diameter at breast height frequency of Clausena dunniana was all interval pattern during the period of succession stages and the population was interval developmental form;The survival curve of Mallotus repandus was nearly DeeveyⅡtype in early succession stage,it was not Deevey type in middle succession stage and it conformed to Deevey Ⅲ in late succession stage;The survival curve of Acercinn amomifolium was all nearly Deevey Ⅲ during the succession period;The survival curve of Clausena dunniana was Deevey Ⅲ in early and late succession stage,but it was disorder in middle succession stage.The research results could provide scientific basis for rehabilitation and reconstruction of degraded karst forest ecosystem.

Key words: karst forest, dominant species, static life table, survival analysis, Maolan