Abstract: In order to explore the infection characteristics of arbuscular mycorrhiza fungi against Glycyrrhiza uralensis and learn the relationship between arbuscular mycorrhiza and growth of G. uralensis and yield of glycyrrhizic acid under different relative water content of soil, potted G. uralensis was taken as the research object to be inoculated with Glomus mosseae, G. versiforme, G. aggregatum and G. Etunicatum separately. By assaying the infection rate of arbuscular mycorrhizal fungi against G. uralensis, stem length, main root length, overground weight, underground weight and content of glycyrrhizic acid after infection, the influence of arbuscular mycorrhiza on the growth and metabolism of G. uralensis under different relative water content of soil was studied. The result showed that the four kinds of arbuscular mycorrhizal fungi inoculated all could form arbuscular mycorrhiza with G. uralensis and abundant arbuscular and vesicle structure was formed with the infection rate as high as above 70%, significantly facilitating the growth of G. uralensis. Under 50% and 65% relative water content of soil, the arbuscular mycorrhiza could hasten G. uralensis growth. When the relative water content of soil was less than 35%, G. uralensis could not grow normally. By comprehensive analysis under different relative water content of soil, the G. uralensis inoculated with G. mosseae showed better growth and contained much glycyrrhizic acid. In general, G. mosseae is more conducive to improving the adaptability of G. uralensis and generates greater growth effect.