Abstract：This article introduces four medical cases of the clinical application of classical formulas in gynecology， namely Danggui Shaoyao Powder， Wenjing Decoction， Jiao'ai Decoction， and Gegen Qinlian Decoction. Danggui Shaoyao Powder has three main effects：first，it promotes blood circulation；second，it nourishes blood，soothes the liver，fortifies the spleen，and drains dampness；third，it harmonizes blood and promotes diuresis. It is mainly used for the treatment of abdominal pain during pregnancy， targeting the pathogenesis of "the liver-spleen disharmony leading to the disease of qi and blood". Wenjing Decoction primarily warms the meridians and dissipates cold，nourishes blood， and dispels blood stasis. It targets the pathogenesis of "cold， stasis， deficiency， and heat"， that is， deficiency-cold of the thoroughfare vessel and conception vessel，static blood obstruction，insufficiency of yin blood， and heat due to stasis and deficiency， and is used for the treatment of irregular intermenstrual bleeding. Jiao'ai Decoction mainly nourishes blood， stops bleeding， regulates menstruation， and prevents miscarriage. It targets the pathogenesis of "the inability of keeping yin qi internally and controlling menstrual blood due to the deficiency of the thoroughfare vessel and conception vessel"，and can be used for the treatment of restless fetus. Gegen Qinlian Decoction is a classic formula for fever with diarrhea， with the main effects of clearing internal heat and venting pathogens. It targets the core pathogenesis of "fullness in the middle and internal heat"， and is used for the treatment of delayed menstruation.