The survey on bird communities was conducted by the belt-style methodinsix different sample plots in the Honghuaerji Forests area in the northern Inner Mongolia in June 2001 and totally 28 bird species were recorded. Vegetatio n investigation was carried out in five 10 m×10 m quadrats at each plot. The as ymptotic regression function formulae were adopted to identify the relationships between the vegetation coverage and the numbers of bird species and individuals . The analytical results showed that the changes of species number and density o f bird as well as the formation of bird communities follow the changes of forest type and the total foliage. Both the number of bird species and their density d ecreased with the decrease of total foliage. The similarity of bird community wa s very low at the breeding time. In the same classification of cluster, no simil arity was higher than 0.65, which indicated that the composition of species had agreat difference between all the bird communities. The bird breeding density w as closely related to forest growth stage. From the bare grassland ecosystem to climax ecosystem, the density of bird species showed a gradually increasing trend.