Abstract: Cyclobalanopsis glauca forest is one of the main types of the evergreen broad leaved forest (EBLF) in East China Subtropical Area.The study on the structure and dynamics of populations of C.glauca forest was carried out in Jiande,Zhejiang,with the methods of contiguous grid quadrats and spatial sere substituting for time sere.On the basis of census of all individuls of main populations in different communities,the size structure,the spatial pattern of the main populations and their dynamics were described.The result shows that size structure of C.glauca and Lithocarpus glaber appears irregular inverted J type,but it is still characterized by stable type.The spatial pattern of the C.glauca populations is a contagious type,which changes with the size classes of the population.It was found that seedling or sapling class show contagious type,while the small and middle tree classes exhibit radom type.The regularity reflects that spatial pattern of the populations changes with time in the development of forests,and moreover,it also embodies the ecology strategy or adaptive mechanism.The spatial patterns of main populations in communities have also been measured,which show that the dominant populations in tree layer appear radom type.In the shrub layer,the seedling or sapling of dominant populations follows contagious type.In the herb layer,the spatial pattern of most populations exhibit contagious type.Additionally,the quantitative structure and dynamics of propagative module of C.glauca clone populations have been studied.According to the above results,the dynamics process or mechanism of C.glauca forest has been discussed preliminarily.