滇緬公路，是國民政府向外求援管道之一。抗戰爆發後，中國海港紛紛淪陷，國府能向外國外求援管道有二：一曰剛開通之滇緬公路，二曰向河內之滇越鐵路。當時中國能套取外匯之物資（錫礦、豬鬃、鎢礦等）咸賴此二路出海。而軍委會等政府機關所需之軍火物資、工廠所需之原料、大後方人民所需之消費品，都仰賴此二路進口。直到1940年日本進佔河內，滇越鐵路遂斷。日軍據河內機場轟炸滇緬公路。但因公路單位搶修，因此一直暢通。日本同時與泰國簽訂中立協定。讓日軍借道泰國西部攻打緬甸，待毛淡棉、仰光失陷，英國商請中國出兵援助之時，業已經過兩個月。當時美國芻議設立中緬印戰區，以蔣委員長為最高統帥。蔣氏基於中美同盟，商由美國派任參謀長，協同計劃作戰，故有史迪威來華。國軍開赴前線，英軍向印度方向撤退，以致平曼納會戰、曼德勒會戰無法開展，致使國軍向北撤退，後方撤退路線亦遭日軍截斷，僅能從森林地帶撤退國內，導致大量官兵傷亡。餘部分別向印度及雲南撤退。

The Burma Road, was a war time artery from Kunming to Port of Yangon. This route also the only route that raw material such as tungsten, bristles, tin and etc essential raw material exported to Western Friends, and imported ammunitions ordered by Military Commission, raw material that factories desperately needed, and also imported consumers goods to the Rear China. This situation until 1940s, the Japanese militarist take Hanoi as tribute to Vichy Government summoned to Germans. Although Japanese bombing the route but the engineers still maintain the route without any disruptions. At the same time, The Japanese and Siamese Government signed a Neutrality Pact; lead the Japanese can pass through Siam to Burma. Until the Port of Yangon and Moulmein was lost, British was forced to request for assistance. The American set up China Burma India Theater, known as CBI Theater in short, Generalissimo Chiang Kai-shek as the supreme commander. Joseph Stilwell as Chief of Staff. This Chinese Army was the famous The Chinese Expeditionary Forces, The Chinese army rush to battle field but the British Army plans to retreat to India. This leads the lost of Pynmana and Mandalay, the retreat route to Kunming was lost too. This Expeditionary Forces suffers of rugged routes, poor of supplies, starvations, many of them commit suicide in forests. Approximately 100 thousand army into Burma, 60 thousand in causalities. Others spread to two groups, one retreated to India, this group becomes Indian Army; the other group retreat to Yunnan, regroup and relocated as The Second Chinese Expeditionary Forces.