Abstract: Based on the 109 plots dataset from the field, the species diversity of wetland vegetation of Sanggan River watershed, Shanxi was studied by using richness indices，species diversity indices and evenness indices, respectively. The different significant among these indices for all communities were studied by analysis of variance and Duncan multiple range test, respectively. The results indicated that: The sequence of the species diversity indices was as follows: Ass. Tamarix chinensis—Potentilla chinensis>Ass. Tamarix chinensis+Hippophae rhamnoides—Roegneria kamoji>Ass. Tamarix chinensis—Potentilla anserina>Ass. Tamarix chinensis—Phragmites communis>Ass. Phragmites communis+Polygonum hydropiper+Cyperus glomeratus>Ass. Phragmites acommunis+Carex dispalata>Ass. Thymus mongolicus+Artemisia gmelinii>Ass. Typha orientalis+Polygonum hydropiper>Ass. Scirpus validus+Chara sp.+ Potamogeton distinctus>Ass. Scripus triqueter+Cyperus glomeratus+Alisma orientale>Ass. Scirpus validus+Scirpus triqueter+Phragmites communis> Ass. Myriophyllum spicatum+typha orientalis>Ass. Sagittaria sinensis+Phragmites communis>Ass. Polygonum hydropiper+Sagittaria trifolia>Ass. Juncellus serotinus+Echinochloa phyllopogon. R₀, H′and E₄ were better than the others by using analysis of variance and Duncan multiple range test, respectively.

Key words: Sanggan River, wetland, species diversity, evenness indices, richness indices, species diversity indices