The Ming-Korean army planned a counterattack against the Japanese army, which was hurried in building castles on the southern coast of the peninsula, and attacked the easternmost castle being constructed, which was Urusan-jo.
朝鮮半島南岸で築城を急ぐ日本軍に対し明・朝鮮軍は反攻を企画し、建設中の城塞群の内最東端に位置する蔚山城に目標を定めて攻撃した。