Abstract: In this paper, the effects of saline-alkali stress on alfalfa were summarized, including the effects of salt and alkali stress on seed germination, growth and development, photosynthesis, osmotic regulation, antioxidant regulation, molecular mechanism of salt alkali, ion balance regulation and so on. Furthermore, the mechanism of alfalfa response to saline-alkali stress was expounded at the same time, the mechanism and feasibility of improving the saline-alkali tolerance of alfalfa through exogenous substances and mycorrhiza was further elaborated, aiming to provide support and practical guidance for planting alfalfa in saline alkali land, realizing ecological restoration of saline alkali land and excavating reserve cultivated land resources.

Key words: saline-alkaline, stress, alfalfa, salt-alkali tolerance