The main function of Yanghe decoction is to warm yang, enrich the blood, invigorate the circulation of blood, dispel the cold and eliminate the phlegm. It can be used to treat blood deficiency, congeal cold, stagnation of Qi and phlegm, dorsal furuncle; Mammary cancer due to liver depression, dysfunction of spleen in transportation, imbalance of Chong-ren, stagnation of Qi, blood and phlegm. The pathogenesis of dorsal furuncle is similar to the mammary cancer. This paper mainly focuses on the mechanism of prescriptions corresponding to syndromes of Qi deficiency mammary cancer treated with Yanghe Decoction.