Arun River (China–Nepal)
| Arun | |
|---|---|
| Native name | Bum-chu (Chinese) | 
| Location | |
| Country | Nepal, China | 
| State | Tibet | 
| Physical characteristics | |
| Source | Gutso | 
| • location | Tibet | 
| Mouth | Confluence with Sun Koshi and Tamur River to form Sapta Koshi | 
|  • location | Tribenighat, Nepal | 
|  • coordinates | 26°54′47″N 87°09′25″E / 26.91306°N 87.15694°E | 
| Discharge | |
| • location | Koshi river | 
| Basin features | |
| Tributaries | |
| • left | Yeru Tsanpo, Trakar-chu | 
| • right | Barun River | 
The Arun River (Nepali: अरुण नदी) is a trans-boundary river that is part of the Koshi or Sapta Koshi river system in Nepal. It originates in the Tibet Autonomous Region of the People's Republic of China where it is called the Phung Chu or Bum-chu.