The invention provides a Chinese medicinal composition for preventing a radioactive oral mucosa reaction. The Chinese medicinal composition comprises the raw materials including acanthopanax root, radix codonopsis, fructus ligustri lucidi, rhizoma belamcandae, semen coicis, herba dendrobii, coptis root, herba houttuyniae, rhizoma anemarrhenae, madder, caulis bambusae in taenian, herba agrimoniae, angelica, radix paeoniae rubra, chrysanthemum, zedoary, herba selaginellae, heterophylly falsestarwort root, uncaria, yam, chimonanthus nitens, indigofera tinctoria, meadow fescue, eleusine indica, conyza japonica, hypericum sampsonii hance, franzenbach rhubarb root and rhizome, jujube, semen cuscutae, buttercup root, balloonflower root, kudzu root, radix bupleuri, figwort and radix changii. The Chinese medicinal composition has a good treatment effect, does not have toxic or side effect, can be used as an auxiliary treatment medicament for radiotherapy and chemotherapy of nasopharyngeal cancer, can be quite beneficial to enhancing the curative effect of radiotherapy and chemotherapy, relieving the radioactive oral mucosa reaction after radiotherapy and improving the quality of life when being simultaneously used in radiotherapy and chemotherapy of a nasopharyngeal cancer patient, and also shows a good prospect for combined treatment of malignant tumors at the same time.