Objective To explore the effect of Chinese medicine liquid to gargle on the oral mucosa reaction in nasopharyngeal carcinoma patients with radiotherapy .Methods One hundred nasopharyngeal carcinoma patients with radiotherapy were divided into the control group and the observation group according to the random number table , each with 50 cases.The control group received anti-inflammatory mouthwash to gargle, which included gentamicin 4 ml, dexamethasone 5 mg, lidocaine 20 ml, NS 250 ml, 5% sodium bicarbonate 250 ml.The observation group received the Chinese medicine liquid to gargle , which included AMUR CORK TREE BARK 25 g, SCUTELLARIA 25 g, DANDELION 25 g, MINT 5 g and were gargled before and after three meals a day, before radiotherapy, before bedtime.The microbiology in oropharyngeal was monitored during the treatment and after radiotherapy according to WHO oral mucosa radiation damage grading criteria . Results The oral mucosa reactions in the observation group were all lighter than those in the control group at the third weekend, the seventh weekend , and one week after radiotherapy , and the differences were statistically significant (Z=37.645,22.880,10.874, respectively;P <0.05).The positive rate of throat swab bacterial culture was 16.0%(8/50) in the observation group , and was 34.0%(17/50) in the control group at the seventh weekend, and the difference was statistically significant (χ2 =4.320,P<0.05).Conclusions Chinese medicine liquid to gargle can effectively prevent and relieve the oral mucosa reaction induced by the radiotherapy for the treatment of nasopharyngeal carcinoma , and reduce oral infection .