Objective:To explore the effect of nutritional intervention on nutritional status and acute radiation oral mucositis in patients with head and neck cancer.Methods:Sixty-eight patients with head and neck cancer received radiotherapy were randomly divided into two groups.There were thirty-three patients in nutritional intervention group(NI),the rest for the control group.The nutritional status score (PG-SGA),mean weight,body mass index (BMI)and acute radiation oral mucositis score in the two groups were before radiotherapy,at the end of radiotherapy,one month after radiotherapy were analyzed and compared.There was no significant difference in PG-SGA scores between the two groups before radiotherapy.The PG-SGA scores in NI remained stable,no difference at between each time point.At the end of radiotherapy and 1 month after radiotherapy,the PG-SGA scores in NI were significantly lower than those in CG (P ＜ 0.001,P ＜ 0.05 respectively),while the nutritional status deteriorated in CG and the scores at the end of radiotherapy and one month after radiotherapy were significantly higher than those before radiotherapy(P ＜ 0.001,P ＜ 0.05 respectively).The mean weight in NI remained stable during radiotherapy.At the end of radiotherapy,the mean weight in NI were significantly higher than those in CG (P ＜ 0.001).While the mean weight in CG were in the declining tendency,and at the end of radiotherapy they were significantly lower than those before radiotherapy P ＜ 0.001).The trend of BMI is the same as that of mean weight.There was no significant difference between the two groups in the incidence of severe acute radioactive oral mucosal reaction (1Ⅲ + Ⅳ grade) (P ＞ 0.05).At one month after radiotherapy,the incidence of total acute radiation mucositis (Ⅰ + Ⅱ + Ⅲ + Ⅳ) and severe acute radiation mucositis (Ⅲ + Ⅳ grade)in NI were significantly lower than those in CG(x2=4.556,P ＜ 0.053,P ＜ 0.05;x 2=4.712,P ＜ 0.05,P ＜ 0.05 respectively).Nutritional intervention can effectively maintain the nutritional status of patients received radiotherapy of head and neck cancer,and promote the recovery of acute radiation oral mucositis.