Abstract: We studied the diversity index of species richness,diversity and uniformity of 16 types of water conservation forests in Badaling forest farm.Results showed that the diversity index change in Xigou pine forest and shaw and black birch forest is in the form of shrub>herb>tree,in other communities it is same with the richness index;in secondary forest of Platycladus orientalis,Robinia pseudoacacia Cotinus coggygria mixed forest,pine forest,Acer truncatum and Huashan pine forest,the diversity index is in the order of herb layer>shrub layer>tree layer,the species diversity among all levels of larch forest community is shrub layer>herb layer>tree layer.

Key words: Badaling Forest Farm, water conservation forest, diversity, index