The Third Field Army was one of the five main forces of the Communist Party's People's Liberation Army during the Chinese Civil War. It was established in early 1949. Initially known as the East China Field Army, it was formed by the New Fourth Army and the Eighth Route Army troops stationed in Shandong Province, a gradual adaptation of the expansion. It took control of the troops in eastern China, with Chen Yi as its commander. It comprised the 7th, 8th, 9th, and 10th Armies plus the headquarters of the special technical troops, with a total of 580,000 men.