The invention relates to a medicament for treating cancers, in particular to a traditional Chinese medicine for treating the lung cancer, which is prepared by using plant Chinese herbal medicines as the raw materials. The traditional Chinese medicine for treating the lung cancer consists of the following raw material medicines in parts by weight: 10 to 20 parts of Paris polyphylla Sm, 5 to 10 parts of unibract fritillary bulb, 5 to 15 parts of rabdosia rubescens, 10 to 20 parts of dried alum, 10 to 20 parts of astragalus, 10 to 20 parts of borneol, 5 to 15 parts of honeysuckle, 5 to 10 parts of ginseng, 5 to 10 parts of lucid ganoderma, 5 to 15 parts of gardenia jasminoides, 15 to 30 parts of Indian bread pink epidermis, 10 to 20 parts of acorus calamus, 5 to 10 parts of andrographis paniculata, 10 to 20 parts of liquorice, 25 to 40 parts of Japanese knotweed, 15 to 25 parts of gnetum parvifolium, 5 to 10 parts of tripterygium wilfordii, 5 to 15 parts of barbed skullcap herb and 5 to 10 parts of hedyotis diffusa. The traditional Chinese medicine for treating the lung cancer, which is disclosed by the invention, is prepared by years of clinical experimental summary, mainly uses the Japanese knotweed, the gnetum parvifolium and the lucid ganoderma for inhibiting cancer cells from growing, is assisted by the ginseng, the liquorice and the astragalus in consolidating basis, has effects of clearing heat and removing toxicity when being matched with other medicaments, and can effectively relieve the symptoms of the lung cancer.