On May 15, Du Yuming gave the order to launch a general assault on Siping and declared to his men that the city must be taken this time. The nationalist assault came in three fronts: the 88th Division and the New 6th Army of the nationalist right front would attack the enemy's left flank, targeting cities including Gongzhuling, Meihekou, Changchun and Qitamu (其塔木). The New 1st Army on the nationalist central front would directly attack city and then would take Shuangcheng and Dehui after taking Siping, and continue its push to the regions north of the Songhua River. Two divisions of the 71st Army on the nationalist left front would attack the enemy's right flank, targeting Zheng Family's Village (Zheng Jia Tun, 郑家屯) and Shuangcheng. On May 15, 1946, with ten times numerical superiority and additional technical superiority, the nationalist 50th Division at the left flank of the nationalist central front launched its fierce attacks under air cover and air support on the peak # 258 held by the enemy, located to the east of Siping and south of Hafu (哈福). After severe casualties, the enemy was forced to give up peak # 258.
