Heilongjiang is a province in northeast China. It is the northernmost and easternmost province of the country and contains China's northernmost point and easternmost point.

Northeast China is a geographical region of China, also called Manchuria in history. It usually corresponds specifically to the three provinces east of the Greater Khingan Range, namely Liaoning, Jilin, and Heilongjiang, but historically is meant to also encompass the four easternmost prefectures of Inner Mongolia west of the Greater Khingan. The heartland of the region is the Northeast China Plain, the largest plain in China, with an area of over 350,000 km2 (140,000 sq mi). It is separated from the Russian Far East to the north by the Amur, Argun, and Ussuri Rivers; from Korea to the south by the Yalu and Tumen Rivers; and from Inner Mongolia to the west by the Greater Khingan and parts of the Xiliao River.