Abstract: The production and planting area of crops are restricted seriously by soil salinization and alkalization because of industrialization development.Salinization and alkalization in plants are abiotic stresses that salty ions of neutral salt and alkaline salt in soil inhibit the growth of plant.Saline-alkali stress can be divided into salt stress and alkali stress.Both salt stress and alkali stress can change the osmotic equilibrium between plant and soil that induce ion poisoning and oxidative stress,while higher pH induced by alkaline ions for plant is serious than neutral salt.Alkali stress can change the pH in plant and reduce the ability of nutrient element assimilation,especially soluble ferric ion.In this review,we summarized the harmful effects of salt stress and alkali stress on plant; the way of sensing and responding to salt stress and alkali stress by reactive oxygen species(ROS),SOS pathway,several plant hormones and epigenetic modification.The common molecular mechanisms in reducing the damage to plant and plant responses to salt and alkali stress were also discussed.