Abstract: The species diversity of five plantation communities,i.e.,Platycladus orientalis,Pinus tabulaeformis,Quercus variabilis,Q.variabilis mixed with Q.aliena,and Robinia pseudoacacia in Jiufeng Forest Park,Beijing was analyzed based on field survey.The following conclusions were drawn: There was evident stratification among the arbor,shrub and herb layers in all of the five plantations,and there was a certain correlation among the species diversity of the layers.The mixed plantation of Q.variabilis and Q.aliena showed higher richness predominance and species diversity by comparing these indices among different communities and layers.Within the shrub layer, there were both higher species diversity and richness in Pinus tabulaeformis and Robinia pseudoacacia plantations.