The Chahar People's Anti-Japanese Army consisted mostly of former Northwestern Army units under Feng Yuxiang, troops from Fang Zhenwu's Resisting Japan and Saving China Army, remnants of the provincial forces from Jehol, Anti-Japanese volunteers from Manchuria and local forces from Chahar and Suiyuan.
The Chahar People's Anti-Japanese Army consisted mostly of former Northwestern Army units under Feng Yuxiang, troops from Fang Zhenwu's Resisting Japan and Saving China Army, remnants of the provincial forces from Jehol, Anti-Japanese volunteers from Manchuria and local forces from Chahar and Suiyuan.
After the failed Second Encirclement Campaign against Shaanxi–Gansu Soviet in July, 1935, Chiang Kai-shek once again immediately mobilized more than 100,000 troops of warlords of Northeast China, Shaanxi, Shanxi, Suiyuan, Ningxia and Gansu to launch the Third Encirclement Campaign against Shaanxi–Gansu Soviet aimed to eradicate the local communists.
The nationalist forces in North China concentrated on protecting important regions including: the Beijing – Shijiazhuang section of Beijing – Hankou Railway, the Beijing – Zhangjiakou section of Beijing – Suiyuan Railway, Northern section of Tatong – Fengling Crossing Railway, Beijing – Shanhaiguan section of Beijing – Shenyang Railway, and the iron triangular region of Beijing – Baoding – Tianjin region.