To explore the correlation of species diversity and aboveground biomass and the vertical variation of species diversity, taking five grassland types in the Buerjin forest area of Altai mountains as the research object, the species diversity change characteristics of various grassland types were analyzed through the investigation of various grassland types in Buerjin forest area in Altai Mountains. The results showed that: (1) There were significant differences in aboveground biomass among the five grassland community types. The aboveground biomass of the desert grassland and mountain meadow grassland was lower, that of the mountain grassland was the highest, while that of the mountain meadow and alpine meadow was between them. (2) There are significant differences in the species diversity index, dominance index, richness index and evenness index among different grassland types. The species dominance, diversity and evenness of alpine meadows were the best, and the abundance of the mountain grasslands was significantly better than that of other grassland types. (3) Aboveground biomass was only significantly related to dominance and diversity in mountain meadow grassland and mountain meadow, but there was no significant correlation between aboveground biomass and species diversity in desert grassland. (4) In the range of 900~2 400 m above sea level, the changes of the species dominance, richness, evenness and diversity index of grassland communities were basically the same, showing a trend of first rising, then falling and then rising, reaching peaks in the 1 200~1 400 and 2 200~2 400 m zones. The results would provide some conference and further understanding for the distribution pattern of grassland and its functions in the Buerjin forest area of Altai mountais.