Objective To discuss the application value of prognostic nutritional index PNI body mass index and N stage before radiotherapy in predicting the clinical outcome of nasopharyngeal carcinoma NPC patients undergoing radiochemotherapy. Method From January 2010 to December 2015 128 NPC patients undergoing radiochemotherapy in No. 416 Hospital of the nuclear industry were selected and retrospectively analyzed their general information treatment plan laboratory examination pathology and imaging data. The clinical outcomes were followed up until December 20 2021. Kaplan-Meier method was used to draw the survival curve. Log rank χ2 Test and Cox regression analysis was used to explore the prognositic factors of nasopharyngeal carcinoma patients. Result The mortality was 21. 88% during the median at 69. 5 months follow- up. The 3 - year and 5 - year survival rates of 128 patients were 94. 53% and 80. 47% respectively. Receiver operating characteristic ROC curve showed that albumin ALB lymphocyte LYM PNI white blood cell WBC and body mass index BMI were statistically significant in predicting the survival rate of patients P< 0. 05 with cut-off values at 37. 5 g / L 1. 75 × 10 9 / L 45. 0 4. 55 × 10 9 / L and 21. 85 kg / m 2 respectively. Univariate analysis showed that PNI ALB LYM and WBC were all risk factors for prognosis while tumor stage T stage N stage and BMI were all protective factors for prognosis. Multivariate Cox regression showed that PNI ≥ 45. 0 and BMI ≥ 21. 85 kg / m 2 were protective factors while N stage 2 to 3 was a risk factor for the prognosis of nasopharyngeal carcinoma patients with HR 95%CI 0. 784 0. 725-0. 847 、 0. 824 0. 700-0. 970 and 4. 289 1. 737 - 10. 589 respectively P < 0. 05 . Conclusion The nutritional status of nasopharyngeal carcinoma patients before radiochemotherapy is related to the clinical prognosis. PNI BMI and N stage can be used as independent prognostic factors of nasopharyngeal carcinoma patients.