The invention discloses a traditional Chinese medicine composition for treating acute mastitis. The traditional Chinese medical science considers that the pathogenesis of the acute mastitis mainly comprises milk accumulation, poor circulation of blood and qi, breast collateral impairment, and heat-transmission and pus-production caused by storing milk for a long time. Therefore, a decoction provided by the invention is prepared by the traditional Chinese medicines: radix berberidis, uniflower swisscentaury root, ampelopsis cantoniensis, rhizome anemarrhenae, caulis trachelospermi, gynura pseudo-china, trogopterus dung, cowherb seed, rhizoma atractylodis macrocephalae, pericarpium citri reticulatae viride and dendrobe which have the effects of clearing away heat and toxic materials, promoting blood circulation to remove blood stasis, and dredging collaterals and removing stasis. Through the clinical tests, the total effective rate reaches up 97.3%, which is significantly higher than that of a control group; and the breast pain and breast lumps in the two groups after treatment are remarkably relieved compared with the conditions of the breast pain and breast lumps before the treatment, and the improvement degree of the treated group is superior to that of the control group. The invention has the advantages that the taking is simple, the treatment cost is low, and no side effect is caused after taking, and is worth popularizing and applying.