The 1858 Treaty of Aigun established today's approximate Sino-Russian border, at a great loss to Heilongjiang's territory.

In 1901, the Chinese Eastern Railway linked Hulunbuir to the rest of northeast China and to Russian Far East.

[7] During the Cultural Revolution, the parts of historical Manchuria inside Inner Mongolia were briefly restored to their original provinces; Hulunbuir was given back to Heilongjiang from 1969 to 1979.

The area is 263,953 km2 (101,913 sq mi) and had a population of 2.710 million in 2004, while the gross domestic product was RMB 21.326 billion.

With at least 58% of possible sunshine in all months and an annual total greater than 2,591.1 hours, sunny weather dominates year-round.