Abstract: The fractal properties of main populations of Sinosideroxylon pedunculatum community in Mulun National Nature Reserve were analyzed using box-counting dimension,information dimension and correlation dimension to reveal the orderliness of spatial distribution of different populations and its difference along with the different scales and hence to understand the spatial occupation of the resources and ecological adaptation as well as fractal variation.The results showed that the spatial pattern of dominant plant populations S.pedunculatum,Ligustrn japonicum and Koelreuteria integrifoliola and rare and endangered plant populations Handeliodendron bodinieri and Pteroceltis tatarinowii had obvious fractal properties in corresponding scales.Both the orders of count-box and information dimensions were S.pedunculatum>L.japonicum>K.integrifoliola>H.bodinieri>P.tatarinowii.The count-box dimension of S.pedunculatum population was the maximum(1.7763),which was near to value 2,indicating high degree of spatial occupation and the dominant position in community.Its information dimension was 1.7206,which was the highest in five populations,reflecting the high degree of pattern intensity.Both the count-box dimension and information dimension of P.tatarinowii population were lowest,were 0.8316 and 0.8990,respectively,indicating low degree of spatial occupation and pattern intensity.It was in an accompaniment position in forests community and its individuals were scattered in space.From 0.5 to 50 m,the gradation of correlation dimensions was S.pedunculatum(1.7314)>K.integrifoliola(1.6688)>L.japonicum(1.6050)>P.tatarinowii(0.7868),H.bodinieri population only appears correlation in biggish scale.The combination of three fractal dimensions implied comprehensively the feature of the spatialpatterns of different population types and the difference in the position of population in community.