Abstract: Dominant trees play an important role in the formation of community environment and structure. Size-class structure and spatial distribution patterns of P.taiwanensis and S.superbapopulationin three 50 m×50 msample plots within theropencedrymion of Huangtian lake forest farm,Jingningcounty,were analyzed in this paper. The results indicated that the size-class of P.taiwanensis was normal distributed,however, there were more footpath individuals in the population. Smaller and bigger trees of the two species were spatially isolated, the sapling stage of the population of S.superba showed aggregation distribution at small scales and random distribution pattern at large scales, while the spatial distribution pattern of the sapling and mature tree of the population ofP. taiwanensisvaried from place to place.Our study showed that there were differences in the ecological needs of two species at different stages of life history, which leads to differences in spatial distribution pattern. Therefore, the size-class structure and spatial distribution of dominant species should be considered when formulating forest management measures.