The Sanjiang Plain is situated in the Northeast China,it’s a low alluvial plain formed by three rivers:Songhuajiang,Helongjiang,Wusulijiang.The plain is one of concentrated distribution areas of marshland and swamp meadows in our country. The vegetation type in the Sangjiang Plain is comprised of forest,meadow and swamp vegetation,in which vegetation of swampy meadow and marshland is dominant,about 74% of natural vegetation.This paper introduced the classification system of vegetation and describes the costituent,construction and distribution of all vegetation types there (figures and photographs of main types),and the formation and succession regularity of swamp vegetation as well,finally comprehensive utilization and necservation of reginal vegetation resources.