Abstract: To explore the afforestation effect of Pinus sylvestris var. monglica plantation on the response regularity and mechanism of soil salinization degree, we analyzed the physiological and ecological characteristics, the afforestation effect index and soil salinization degree of relationship. The results showed that, as soil salinization degree aggravating, the salt, Na+ and Cl- content increased and the moisture content decreased; Net photosynthetic rate and water use efficiency had negative correlation with total salt, content of Na+, Cl-, while afforestation survival rate, the tree growth were positively correlated. At the same time, along with the soil salinization degree aggravating, the population would be more biomass allocation to root growth and development. Thus, as the soil salinization degree aggravating, soil moisture content, net photosynthetic rate and water use efficiency and biomass allocation proportion dropped on the ground, thereby resulting in impaired the ability of mongolica to survive and grow. Therefore, we must improve the effect of afforestation of salinization area from the lower soil salt content, improve soil moisture conditions.