Objective To observe the preventive and therapeutic effect of Yangyin Shengxue Mixture （Herbal decoction for nourishing yin and blood） on radiation-induced oral mucosal injury.Methods Sixty nasopharyngeal carcinoma patients were randomized into two groups: treatment group （30 cases） receiving Yangyin Shengxue Mixture three days before till one week after radiotherapy

and control group （30 patients） using conventional Tinidazole Gargle for prevention of oral-mucositis. Before and after treatment

the body weight

hemoglobin and state of infection of patients were examined. The time of occurrence of symptoms

degree of acute radiation mucositis and degree of pain were observed to evaluate the damage of oral mucosa according to RTOG standard for radiation injury of oral mucosa and Numeric Rating Scales （NRS）. Results There were different degrees of radiation mucositis in both groups during radiotherapy

but the time of occurrence in the treatment group was significantly later than that of the control group （P<0. 05）. And the number of cases of III and IV degree of injury of oral mucosa and medium and severe pain in the treatment group were both less than those of the control group. The decrease of body weight and hemoglobin and incidence of candida albicans infection in the treatment group were also less than those of the control group （P<0.05）.Conclusion Yangyin Shengxue Mixutre can postpone the development of radiation injury of oral mucosa

decrease the degree of damage

and relieve pain.