Abstract: ob＜x＞jective To evaluate the nutritional status of nasopharyngeal carcinoma (NPC) patients with chemoradiotherapy by Scored Patient-Generated Subjective Global Assessment (PG-SGA), and explore the value of this method in the activity of nutritional intervention. Method 60 NPC patients treated with concurrent chemoradiotherapy from September 2019 to November 2020 were randomly divided into two groups. The experimental group was assessed with PG-SGA, individualized enhanced nutrition counseling and ONS were prescribed to the patients with grade B ≥ 2. Patients in the control group were given routine nutritional counseling and oral nutritional supplementation. Toxicity and side effects were evaluated by RTOG during radiotherapy. ,Nutritional status of BMI、ALB、HB were recorded. Result The differences in PG-SGA and BMI between the two groups at different time during treatment were statistically significant(P＜0.05). ALM and HB of patients in the experimental group were significantly better than those of the control group at 20 fractions of radiotherapy and at the end of radiotherapy(P＜0.05). There was no significantly different in the score of xerostomia between the two groups(P＞0.05) at the end of radiotherapy. The scores of radiation dermatitis and oral mucositis of patients in the experimental group were lower than those of the control group(P＜0.05). Conclusion Nutritional intervention assessed by the PG-SGA can significantly reduce the acute radiation toxicity and improve the nutritional status ,quality of life and treatment compliance of NPC patients during chemoradiotherapy.