In　this　study,　We　investigated　the　abundance　and　distribution　of　microplastics　in　the　upper　main　stream　of　the　Wuding　River,　a　first-order　tributary　of　the　Yellow　River,　and　the　tributaries　of　the　Nalin　River,　the　Hailiu　Rabbit　River,　the　Yuxi　River　and　the　Lu　River.　The　results　showed　that:　The　average　abundance　of　microplastics　in　the　water　bodies　of　the　upper　Wuding　River　Basin　was　15.58n/L,　ranging　from　2.5　to　35.63n/L.　Microplastic　types　were　abundant,　with　the　percentages　of　PEG　(62.96%),　PE　(6.17%),　PPS　(3.09%),　4-vinylbiphenyl　(2.78%),　PCTG　(2.47%),　PS　(2.16%),　PTFE　(2.16%),　PPSU　(1.85%),　PMMA　(1.54%),　others　(14.81%).　More　than　96%　of　the　microplastics　were　less　than　1mm,　which　was　very　easy　to　enter　the　enrichment　of　organisms.　The　shape　is　dominated　by　fragments,　followed　by　films　and　granules;　most　of　them　were　transparent　or　brown,　and　other　colors　accounted　for　about　25%.　Based　on　the　source-specific　classification　system　of　microplastics,　it　was　initially　determined　that　microplastics　mainly　originated　from　agricultural　mulch　film　and　personal　toiletries.　The　results　indicate　that　the　overall　risk　of　microplastics　in　water　bodies　in　the　upper　watershed　of　the　Wuding　River　was　at　a　mild　pollution　level.　The　abuse　of　toxic　and　harmful　plastics　was　of　particular　concern.　The　study　of　microplastics　in　the　upper　Wuding　River　basin,　which　is　located　in　the　windy　beach　area　in　the　southeastern　part　of　the　Mawusu　Desert,　on　the　one　hand　reveals　the　current　status　and　potential　pollution　risk　of　microplastics　in　the　windy　beach　area;　on　the　other　hand,　it　provides　a　typical　case　of　scientific　understanding　of　the　impact　of　urban　development　and　agricultural　production　on　the　water　environment　in　the　desert　area　from　the　perspective　of　microplastics.　©　2023　Chinese　Society　for　Environmental　Sciences.　All　rights　reserved.