After completing its training, the division took part in the North Korean advance from Seoul to Taejon, reaching Tilksong on 10 August. After this it took part in The Great Naktong Offensive during the Battle of Pusan Perimeter, suffering heavy casualties before withdrawing in late September, leaving behind all its artillery. These losses hampered the division's actions when it returned to the fighting in the New Year and the only indirect fire support weapons it possessed at this time were mortars. In June 1951, after undertaking guerrilla operations during which a large portion of the division was isolated behind UN lines, the division reorganized around Kunch'on and was transferred from II Corps to IV Corps.