Oriental lily species ‘Siberian’ and arbuscular mycorrhizal fungus Funneliformis mosseae and Glomus versiforme were used as materials in this experiment. The NaCl stress (0, 0.4%, 0.8% and 1.2% NaCl solution treatment) and inoculation with AM fungi ［inoculation with F. mosseae, G. versiforme, F. mosseae+G. versiforme and noninoculation treatment］ were tested in two factors under greenhouse conditions. We analyzed the characteristics of hormone balance and cell permeability of lily under different treatments, in order to evaluate the effect of AM fungus on salt tolerance and explore the mechanism of AM fungus enhancing salt tolerance of lily. The results showed that: (1) AM fungus could effectively increase the plant height and biomass of lily plants under salt stress, and significantly improve the salt tolerance of lily. The double inoculation treatment resulted in the increase of plant height, dry weight above ground and underground, reaching 8.9%, 14.5%, and 11.2% respectively as compared with the uninoculated control under 1.2% NaCl stress. (2) AM fungus can significantly increase the contents of mineral element P, K, S and reduce the contents of Na and Fe in leaves of lily plants under salt stress. Compared with the control, the contents of P, K and S in leaves of lily plants with double inoculation treatment were increased 10.9%, 8.3% and 13.7%, while their Na and Fe contents decreased by 28.4% and 66.4% respectively. (3) AM fungus can significantly increase the contents of endogenous hormone indoleacetic acid and abscisic acid under salt stress. The double inoculation treatment was 1.2 times and 1.5 times higher than that in the control under 1.2% NaCl stress, respectively. (4) AM fungus can significantly increase the soluble protein content of lily and significantly decrease its proline content under salt stress. The increase and decrease amplitude of double inoculation treatment was 69% and 31% under the 1.2% NaCl stress. (5) AM fungus can significantly reduce the malondialdehyde content and relative conductivity of lily leaves under salt stress. The double inoculation treatment decreased by 58.1% and 9.0% under the stress of 1.2% NaCl, respectively. It can be seen that AM fungus can enhance the tolerance of lily under salt stress by enhancing the absorption of nutrients, reducing the damage caused by oxidative stress, regulating the balance of endogenous hormones and cell permeability, and the effect of double inoculation is better than that of single inoculation.