Tracing the provenance and understanding the mechanisms of aeolian- fluvial interaction in large sandy lands located in arid and semi- arid regions are essential for comprehending the evolution of terrestrial landscape patterns, surface processes and geomorphological dynamics, and the linkages between the atmosphere and lithosphere. However, the provenance of the Horqin sandy land remains highly controversial, and there is a lack of a statistically significant zircon U- Pb age database. Therefore, this study aims to address these gaps by conducting multi- point sampling of surface aeolian sand from the Horqin sandy land and analyzing 1500 detrital zircons using U- Pb dating analysis based on different grain sizes (i. e., <63 μm and >63 μm). Subsequently, the inverse Monte Carlo model is employed to quantitatively constrain the provenance of the Horqin sandy land. The visual qualitative analysis of detrital zircon U- Pb age spectra in the Horqin sandy land revealed striking similarities. However, the quantitative reconstruction provided a more detailed understanding of the sources of the aeolian sands. It showed that the Central Asian orogenic belt contributed significantly to the overall composition of the aeolian sands (ranging from 50. 5% to 61. 3%). In contrast, the southeastern part of the Horqin sandy land exhibited a dominant contribution from the North China Craton (~75. 8%). The sources of the Horqin sandy land displayed spatial heterogeneity, with the western and northern parts exhibiting highly similar zircon age spectra that differed significantly from those in the southern part. The impact of grain- size sorting on the detrital zircon U- Pb age signature was minimal, except in the southeastern part of the sandy land. Thus, we suggest that the synergistic effect of wind, fluvial processes, and subsequent sedimentary sorting and recirculation are the primary drives behind the U- Pb age signature of detrital zircons in the Horqin sandy land. Combined with the regional tectonic evolution history, the peak ages observed at ~2. 5 Ga and ~1. 85 Ga in the Horqin sandy land are attributed to two tectonic events during the growth, collapse and collision of the North China Craton in the early Precambrian, respectively. In addition, the ~1. 7 Ga zircon age may be a consequence of the convergence and rifting of the Columbia supercontinent. The peak ages of zircons (e.g., 500~400 Ma, 300~250 Ma, and 130~110 Ma) since the Paleozoic era denote multiple regional tectono- magmatic events associated with the subduction and closure of the Paleo- Asian Ocean, the subduction and collision of the Mongolian- Okhotsk Sea, and the subduction and retreat of the Paleo- Pacific Ocean, respectively.