Longjiang County is a county of Qiqihar City, Heilongjiang Province. Longjiang County is located in the southern foot of the Great Khingan Mountains and Songnen Plain transition zone, Yaru River. Longjiang County is a famous multi-grain production area, animal husbandry county, Longjiang County covers an area of 6175 square kilometers. According to the seventh census, as of midnight on November 1, 2020, the permanent population of Longjiang county was 414,285.

Longjiang County has Longxing Town Zhang Mansion, Shajiajie Ancient City site, the Golden Great Wall site, Jingxing Town Jar Kiln site, Qishu Town Wanghai Site and other historical and cultural sites. Is the national cultural advanced county.
On September 25, 2018, it was awarded the honorary title of "2018 E-commerce into Rural Comprehensive Demonstration County" by the Ministry of Commerce. On May 5, 2019, Longjiang County was approved by the provincial government to be removed from the poverty-stricken county list after deliberation by the Leading Group of Poverty Alleviation and Development of Heilongjiang Province. In November 2019, it was selected into the list of the second batch of counties (districts) that reached the standard of water-saving social construction.

In 2020, the GDP of Longjiang County reached 12.59 billion yuan, with a year-on-year growth of 8.6%; The planned industrial added value reached 3.17 billion yuan, a year-on-year growth of 17.3%; China's investment in fixed assets reached 2.32 billion yuan, up 15.3% year on year; General public budget revenue reached 620 million yuan, up 18.8% year on year; Local tax revenue reached 444 million yuan, up 22.6% year on year; The per capita disposable income of urban and rural residents rose by 2.6% and 8.5% respectively. Retail sales of consumer goods fell 12.3 per cent year on year.