The damage of saline-alkaline stress on plants could be divided into osmotic stress, ion toxicity and high pH stress. Seed germination, growth and development, and gene expression of plants could be affected by varying degrees of saline-alkaline stress. Studies on the mechanism of saline-alkaline stress on plants could help to find effective measures to improve saline-alkaline tolerance of plants. On the basis of previous studies, this research elaborated mechanism of saline-alkaline stress on plants, and analyzed the response mechanism of plants to saline-alkaline stress from seed germination, growth and development, gene expression. This paper put forward some measures to improve saline-alkaline tolerance of plants, which was cultivating strong saline-alkaline tolerant plant varieties,chemical regulation and reasonable nutrient management. It was aim to improve the saline-alkaline soil and providing theoretical basis of improving the saline-alkaline tolerance of plants.