Abstract: To analyze the stand spatial structure of Cunninghamia lanceolata-broadleaved mixed plantation,the plantation predominated by C.lanceolata and Schima superba in mid-subtropical zone was taken as the study object,and three structure parameters (mingling degree,neighborhood comparison and uniform angle index) and two tree species composition(Ⅰand Ⅱ) were used.The results showed that the mingling degree of C.lanceolata and S.superba was mainly relatively weak and moderate mixture,the average mingling in the stand were 0.45 and 0.52 respectively,showing the relatively simple spatial allocation and poor mixing of different tree species in this plantation.The proportions of neighborhood comparison of C.lanceolata, S.superba and Castanopsis sclerophylla distributed uniformly,the mean value was about 0.50. But the differentiation between dominant species (Paulownia, Pinus massoniana and Castanopsis fargesii) and suppressed species (Schima argentea, Toxicodendron verniciflua, Liquidambar formosana, Cyclobalanopsis glauca and Daphniphyllum oldhamii) was obviously, the mean values ranged from 0 to 0.88,indicating the stand growth was mainly medium state,and tree species in the arborous layer was instable.As for uniform angle index, considering the spatial units, the distribution of uniform angle index changed with a fluctuant pattern and the forest plantation presented an aggregating distribution pattern. In order to improve plantation quality and play its function better, this study aimed to provide scientific basis for guiding selective cutting management and spatial structure optimization of C. lanceolata-broadleaved mixed plantation.