Based on the vegetation community survey of a 1 hectare plot in Forest Farm of Mulanweichang,and by using the mingling degree,neighborhood comparison and uniform angle index,the spatial structure characteristics of nature secondary forest in rocky mountain area of Northern China were analyzed.The results showed that Betula platyphlla was the dominant and constructive species of the tree layer,its mingling degree was low,but the mingling degrees of sub-dominant and associated trees were big.The mainly mixed forms of the stand were none-mixed or less-mixed,the average mingling degree was 0.400.The order of tree species neighborhood comparison was as follow: Larix principis-rupprechtii,Sorbus pohuashanensis,Quercus mongolica,Betula dahurica,B.platyphlla,Picea wilsonii,Populus davidiana,Pinus tabulaeformis and Acer truncatum.In the vegetation community,most of the trees were in the random distribution,but the average uniform angle index of the stand was 0.562,so the distribution pattern of the overall stand was aggregative distribution.According to the spatial structure characteristics of nature secondary forest,the tendency of community succession and some management advices were proposed.