［Objective］ Using the chemical element records of surface sediments in Horqin sandy land as an entry point， this study aims to reveal the degree and spatial characteristics of chemical weathering， analyze the main factors influencing the chemical weathering of surface materials， and provide a scientific basis for further understanding the migration processes of surface materials in Horqin sandy land， as well as for its ecological protection and restoration efforts. ［Methods］ 118 surface sediment samples from Horqin sandy land， and were collected and analyzed multiple chemical weathering indices， including chemical alteration index（CIA）， plagioclase weathering index（WIP）， plagioclase index of alteration（PIA）， Compositional varibability index （ICV）， and geochemical triangular diagrams were utilized to assess the spatial weathering characteristics of the surface sediments in Horqin sandy land. Meanwhile factors influencing regional weathering were also investigated. ［Results］ ① Horqin sandy land as a whole was in the initial stage of chemical weathering， with insignificant differences in weathering degree among different types of sandy land. The chemical weathering intensity in the southwestern and central regions was slightly higher than in other areas. while the surface sediments exhibited low maturity and were primarily composed of first-cycle sediments. Weathering was dominated by plagioclase weathering， in the stage of Na and Ca leaching. ② Provenance discriminant diagrams and binary functional diagrams indicated that the geochemical characteristics resembled those of intermediate-acid granites. This confirmed that the parental rocks of the sediments were mainly derived from intermediate-acid granites. The rock types and mineral composition of the source area determined the initial conditions for weathering， thereby influencing the weathering process. ③ Climatic conditions were a significant factor controlling weathering. Chemical weathering intensity in the western part of the sandy land correlated with temperature， while in the eastern part， it correlated with precipitation. Additionally， sedimentary differentiation also caused variations in CIA values， consequently affecting chemical weathering intensity. ［Conclusion］ Chemical weathering in Horqin sandy land exhibits an ‘overall weak but locally heterogeneous’ pattern： Provenance attributes （intermediate-acid granites） establish the weathering foundation， climate drives spatial differences， and sedimentary differentiation processes further exacerbate the variations in weathering intensity.