Abstract: After early spring burning,the density,diversity and richness of grass species are increased and their evenness is decreased.but it is the contrary after later spring burning.Whether early or later spring burning, the height of the community is decreased,especially in the later burned plot.Burning can promote the growth vigour of Aneurolapidium chinense,which is more significant in the later burned plot. After burning,the leaf production of A.chinense is increaed,and the ratio of leaf to stem is the maximum in the later burned plot.The underground biomass of the community is increased in early burned plot,but decreased in later burned one.

Key words: Songnen grassland, Burning, Community characteristics, Aneurolepidium chinense, wheat stripe rust, meteorological grade forecast, winter reproductive area in Sichuan Basin