The Chinese People's Liberation Army (PLA) Kunming Military Region took responsibility for Chinese operations in Lào Cai direction, which involved the 11th and 13th Armies from the Kunming Military Region itself, and the 14th Army from the Chengdu Military Region, totaling about 125,000 troops [REF].
For the Vietnamese side, historians believe that the defense of the Hoàng Liên Sơn Province (modern-day Lào Cai and Yên Bái Provinces) was conducted by several regiments of the Vietnam People's Army (VPA), some of which consisted of the regular 345th and 316th Divisions [REF].