Abstract: Saline-alkali soils in the horqin region of Inner Mongolia were used as the research object,and soil samples of saline-alkali soils 0-20,20-30 cm and 30-50 cm under different treatment measures were collected to analyze the changes of their soil aggregate composition and carbon and nitrogen contents.The experimental treatments were divided into two gradients moderate M and severe L,blank treatment（MCK,LCK）,fine sand spreading treatment（MS,LS）,organic matter treatment（MY,LY）,humic acid treatment（MF,LF） and desulfurization gypsum treatment（MT,LT）.The effects of anthropogenic treatment measures on saline-alkali soil agglomerate fractions and carbon and nitrogen were studied to reveal the mechanisms of soil organic carbon and total nitrogen sequestration under different treatment measures,in order to provide a reference basis for reasonable treatment measures.The results showed that the mechanical stability of soil aggregates was dominated by ＜0.25 mm and 0.25-2.00 mm particle size in the moderately saline control and 4 different treatment measures,and ＞5.00 mm particle size in the heavily saline-alkali;compared with the moderately saline-alkali control,the ＜0.25 mm particle size in different soil layers increased significantly in the 4 treatment modes;compared with the heavily saline control,the ＜0.25 mm particle size in the 0-20 cm soil layer increased significantly.Compared with the control,soil organic carbon increased to different degrees under 4 different treatment measures in different gradients（moderate and severe）,MF＞MY＞MS＞MT,and decreased with the deepening of the soil layer,with the characteristic of surface rectangle;compared with the control,soil total nitrogen increased to different degrees under 4 different treatment measures in different gradients.Compared with the control,moderate saline-alkali 0-20 cm soil layer MS＞MF＞MY＞MT,other MF＞MS＞MY＞MT,severe saline-alkali 0-20 cm soil layer MF＞MS＞MY＞MT,20-30 cm soil layer MF＞MY＞MS＞MT,30-50 cm soil layer no significant difference MF was lower than other treatments and decreases with the deepening of soil layer.Compared with the control saline-alkali bare ground,different treatment measures can effectively improve the soil aggregate characteristics and optimize the main physicochemical properties of the soil,among which the addition of humic acid is the best treatment measure.