Abstract: Data were collected in 1965, 1983, 1994 and 2000 to monitor changes in species diversity and life form spectrum of the subalpine meadow in Dongling mountainous area in the western part of Beijing municipality. The results show that diversity has been declining from 1965 to the present, and the rate of decline has become much higher since the 1980s. Use of importance values ( IV ) to describe life form spectra demonstrates that the life form spectra of the meadow communities has changed greatly since 1983, showing the side effects of the tourism on the appearances of the meadow. Specifically, height of the meadow communities became shorter, species composition changed, and coverage decreased, all in step with a continual increase in horse population that accompanied tourism development during the period from the early 1980s to the present. The results suggest that over-browsing by horses was the main cause of diversity loss and meadow ecosystem degradation. According to the problems existing in the tourist spot of Dongling mountainous area, we suggest that the local departments concerned should determine rational limits for tourism. In particular, we recommend rigidly restricting horse browsing around the meadow, shutting down the sites for horse racing and the tent for browsing horses in the spot as soon as possible, and reinforcing awareness-building programs. In general, the area should be managed for the conservation of biodiversity as well as for development, and the service functions of the ecosystem should be emphasized so as to realize the sustainable use of meadow resources in the mountainous area based on protection of the ecological environment.