The Northeast Counter-Japanese United Army was the main Counter-Japanese guerrilla army in Northeast China (Manchuria) after the Japanese invasion of Manchuria in 1931. Its predecessors were various Counter-Japanese volunteer armies organized by locals and the Manchuria branches of the Chinese Communist Party (CCP). In February 1936, the CCP, in accordance with the instructions of the Communist International, issued The Declaration of the Unified Organization of Northeast Counter-Japanese United Army and marked the official formation of the organization.

Yang Jingyu, born Ma Shangde, was a Chinese communist, military commander and political commissar who led the First Route Army of the Northeast Anti-Japanese United Army during the Second Sino-Japanese War. His troops waged a guerrilla war against Japanese forces in Manchukuo (Manchuria) who were attempting to suppress resistance in the region.