Objective To observe the clinical effect of Kuiyangyou preventing and treating nasopharyngeal carcinoma acute radiodermatitis. Methods Seventy-four nasopharyngeal carcinoma patients by radiotherapy were randomized into the treatment group（ 38 cases） and the control group（ 36 cases）. Both groups were given radiotherapy adopting three-dimensional conformal adjusting technology. On the first stage

the radiation dose was 56- 60 Gy

reduced field boost to 66- 76 Gy at nasopharyngeal neoplasms lesion

median dose 70 Gy. Give radiotherapy from Monday to Friday

33- 38 times in total. After the first time of radiotherapy

patients in the treatment group and the control group applied Kuiyangyou or trolamine cream respectively to radiation field skin evenly and out of 1 cm range

thickness of about 1- 2 mm. Apply once 3 h and 6 h after radiotherapy. Grade the radiation field skin adopting The Radiation-Induced Skin-Reaction-Assessment-Scale（ RISRAS） and radiation therapy oncology group（ RTOG） scoring standard. Record the side effects. Observe each patient for 6 weeks. Results All patients completed radiotherapy successfully. The RISRAS scores in both groups increased with the rise of the radio dose. From the third week

RISRAS score in the treatment group was obviously lower than that in the control group（ P < 0. 05）. When treating for the sixth week

the incidence of radiodermatitis of Ⅱ and more grades in the treatment group was 13. 1%

obviously lower than 33. 3% in the control group（ P < 0. 05）. Conclusion Kuiyangyou could prevent and treat radiation damage of nasopharyngeal carcinoma patients ’ radiation field skin effectively and release the symptoms of acute radiodermatitis.