formerly Nonni River
River, northeastern China.
It is the main tributary of the Sungari (Songhua) River. It rises on the eastern slopes of Da Hinggan Range in northern Heilongjiang province and flows south, forming part of the border between Heilongjiang and Jilin provinces and watering the fertile northern section of the Manchurian plain. It is about 740 mi (1,190 km) long and is an important route; much of it is navigable.