Sumdorong Chu, referred to as Sangduoluo He in the Chinese media, is a tributary of the Nyamjang Chu river that flows along the disputed Sino-Indian border between the Cona County of Tibet and the Tawang district of Arunachal Pradesh. It originates in the Tokpo Shiri Glacier, about 7–10 kilometres east of Nyamjang Chu, and flows down to the river. Its junction with Nyamjang Chu is to the north of that of Namka Chu, another contested river valley, by about two kilometers.