As a very important cross-border river in South Asia, the Koshi River stretches over China, Nepal and India. Endowed with large altitude difference, diverse land cover types and ecosystem integrity, the Koshi River Basin is a sensitive region for land cover and global climate change. By superposing background data of land use with DEM and TRMM3B43, we analyzed the structure and spatial distribution characteristics of land cover types in the Koshi River Basin in detail, and further examined the correlation between land cover types and topography and meteorological factors. Results demonstrate that: (1) land cover in the Koshi River watershed is composed of a total of fourteen types, namely, bare land, forest, shrub, dry land, paddy field, build-up areas, rivers, lakes, glaciers, shoals, saline land, woody plantation, swamp, and grassland, among which paddy field occupies a largest area, accounting for 32.56% of the basin area, followed by forest taking up 18.89%. (2) Terrain factor has huge impact on land cover, which presents vertical zonality from south to north varying in the order of paddy field, forest, dry land, shrub, bare land, glacier and grassland. (3) Land cover type is closely related to climate factors. With the increase of precipitation, the preponderant land cover types are in the order of bare land, grassland, shrub, glacier, forest, and paddy field. Researching the land cover types in the Koshi River Basin is of great theoretical and practical significance, and could also provide basic data for the Belt and Road Initiative proposed by China.