Abstract: Opencast coal mining in Hulun Buir grassland area has resulted in a large destruction of land and vegeta- tion,and the ecological reclamation is difficulty. Arbuscular mycorrhizal fungi can form mycorrhizal symbiosis with more than 80% of higher plants,which can promote the growth of vegetation and accelerate the vegetation restoration in mining areas. With yellow flower alfalfa as the test material,the effects of three kinds of arbuscular mycorrhizal (Funneliformis mosseae,Glomus etunicatum,Glomus versiforme) inoculation on the plant infection rate,the growth, physiological and nutritional characteristics, and soil mycelium density in the opencast mining area were studied through pot experiment in the greenhouse. The results showed that all three strains could form a good symbiotic relationship with yellow flower alfalfa,and the degree of affinity between different strains and host plants was different. Compared with CK treatment,plant height and SPAD value in the three inoculated treatments were significantly in- creased,which the plant height increased by 9． 9% to 23． 5% ,and SPAD increased by 17. 6% to 21． 0% . Inoculation of Funneliformis mosseae significantly increased plant aboveground biomass and root biomass,leaf soluble protein con- tent,and plant leaf net photosynthetic rate,transpiration rate,stomatal conductance and root phosphorus concentration. Inoculation of Glomus etunicatum significantly increased plant aboveground biomass,leaf soluble protein content,tran- spiration rate,and plant aboveground and root phosphorus concentration. Correlation analysis indicated that the mycor- rhizal infection rate was correlated with biomass,leaf soluble protein,stomatal conductance,the ground part N concen- tration,and also significantly correlated with hyphal density,transpiration rate,plant height,root system P concentra- tion. There was a synergistic effect between mycorrhizal infection rate,hyphal density and plant growth,physiological, and nutritional status. The three strains of inoculation had different degrees of promoting effect on the growth of yellow flower alfalfa seedlings,among which Funneliformis mosseae was the best,Glomus etunicatum was the second,Glomus versiforme was the worst.