Abstract: According to the fieldwork data, the species diversity and similarity are analyzed and compared. The results are as follows: There are 67 understory Plants among 11 forestry community types. Shrub plants are 19. Shrub layer’richness is higher than herb layer. Two kinds of diversity indexes show the similar trend. There are no certain laws between shrub and herb’evenness. Poplar forest and the mixed forest of Larch and Birch has the lest similarity among shrub layer. The mixed forest of Spruce and Birch and Birch forest、Birch forest and the mixed forest of Larch and Birch have the highest similarity.