Microplastics (MPs) are widespread in various environments worldwide, they pose a serious threat to ecosystems. As a typical remote area, the Qinghai-Tibetan Plateau (QTP) has a sophisticated road system. However, the contributions of anthropogenic and natural factors to MP accumulation in remote plateau regions remain unclear. Here, we investigated the distribution, driving factors, and main sources of MPs in the source area of Yellow River on the QTP. MPs in soil showed an average abundance of (75.39 ± 49.16) items/kg, which was approximately 1-10