The Northeast Anti-Japanese Allied Forces is an anti-Japanese armed force directly led by the Communist Party of China. In the 14 years of arduous struggle, the Communist Party of China in the Northeast has attached great importance to Party building and has always adhered to the Party leadership and the people's position in political construction. In ideological construction, it has urged Party members to strengthen theoretical study and transform non-proletarian ideology. In organization construction, it has developed and strengthened the Party organization, especially paying attention to the training of Party members and cadres. In discipline and work style construction, it has emphasized to observe Party discipline and be loyal to the Party. The Party building of the Northeast Anti-Japanese Allied Forces cast the soul of the army, expanded the influence of the Party in Northeast China, and enriched the content and form of Party building in practice. The Communist Party of China is about to celebrate its centenary, and revisiting the Party building of the Northeast Anti-Japanese Allied Forces has important theoretical and practical significance for Party construction in the new era.