The 9th Army Group began moving into Korea on November 5th. After the 20th CCF Army had moved into Korea, the 27th CCF Army followed, moving east to Changjin town and covered the road north. They ordered the 79th Division to attack Yudam-ni from the north. East of the Chosin, the 80th Division, with one regiment of the 81st attached, would attack and destroy the army forces there. By November 29th, General Song realized his offensive was not going well. The forces at Yudam-ni had failed to break into the perimeter. That evening he changed his plan and shifted his principal effort to the 31st RCT east of the reservoir. He committed the two additional regiments of the 81st Division to the attack, with, possibly an additional regiment of the 90th Division.

In September 1952 the 24th CCF Army replaced the 27th CCF Army
and they rotated the 27th CCF Army back to China.