The invention relates to a Chinese medicinal herb composition for treating proliferation of mammary glands. The Chinese medicinal herb composition is divided into a formula for oral administration and a formula for external application and comprises the following components: bottle gourd peel handle, buffalo horn, pink herb, coffee senna seed, romanet grape root, shrubby cordyline leaf, honeysuckle rattan, muskroot-like semiaquilegia root, sappan wood, geranium wilfordii, teucrium viscidum root, small centipeda herb, nutgrass galingale rhizome root, dried lacquer, crab bone, cassia seed, Chinese brake herb, wild red bayberry, seedling root and Sinkiang arnebia root; the components in the formula for oral administration are the same as those of the formula for external application, and the dosage of the components in the formula for external application is greater than that of the components in the formula for oral administration. According to an administration method, one bag of the components is taken each day, a bag weights 20 grams, and the components in the formula for oral administration are infused by a half cup of boiling water after dinner and are mixed with 50 milliliters of yellow wine after being melted to be taken while the water is hot; and according to the formula for external application, the components are ground into coarse powder, the coarse powder is put into a bag to be sealed and steamed in a pot, and the steamed coarse powder is applied to affected parts of breasts externally for 40 minutes every time, the medicinal bag is put into a plastic bag for later use for the next time after being used, and the medicinal bag can be used for 8 to 10 times. The Chinese medicinal herb composition has the effects of soothing liver, regulating qi, reducing phlegm, softening mass, promoting blood circulation, removing blood stasis, clearing and activating channels and collaterals.