By applying the method of "spatial sequence as a surrogate for temporal change",size structure of Schima superba population was analyzed with diameter as the indices of individual size.The results showed that in the early period after S.superba population invaded the forest of Pinus massoniana or Liquidamber formosana,size structure of the population was characterized by a growing type(growing,stable and senescent form).And in the processes of succession,the density sequences of S.superba population declined.Through analyzing dynamics of S.superba population,it showed that S.superba population had the characteristic of climax pioneer species, which was different from not only pioneer species such as P.massoniana,and shade-intolerant tree species such as L.formosana,but shade-tolerant tree species such as the Cinnamomum and the Castanopsis.S.superba tree were in the middle position of the forest succession stages.