The invention discloses a traditional Chinese medicine for treating periodontitis. The traditional Chinese medicine is prepared from the following raw materials according to a weight ratio: 10-20 of anemarrhena, 15-25 of gypsum, 10-25 of gardenia, 5-15 of reed root, 10-20 of dried rehmannia root, 30-50 of isatis leaf, 30-50 of rhizoma coptidis, 3-8 of phellodendron bark, 5-15 of balloon flower, 10-25 of pubescent angelica root, 10-20 of ledebouriella seseloides, 20-45 of mint, 10-20 of herba schizonepetae, 5-15 of Ligusticum wallichii, 20-40 of gentian root, 5-15 of notopterygium, 10-20 of psoralea, 40-60 of pipewort, 5-15 of medlar, 5-15 of eucommia, 10-25 of cowpea, 10-20 of yam, 15-30 of gordon euryale and 20-40 of epimedium. The traditional Chinese medicine for treating periodontitis disclosed by the invention has good actions of clearing away heat and toxic materials, diminishing inflammation and sterilizing, eliminating swelling and alleviating paint, tonifying kidneys and consolidating teeth and the like, and has good treatment effects on gum swelling, bleeding and paint, gingival recession, purulent discharge of pocket, loosening of teeth and other periodontitis symptoms.