Abstract: Objective : To cxpk the prognostic factors of patients with nasopharyngeal carcinoma (NPC) after treatment and establish a predictive model of prognostic index (PI) for physicians to give individualized treatment regimen. Methods :From December 1996 to December 1997, 406 patients with nasopharyngeal carcinoma who were treated in our department were analyzed retrospectively. Prognostic factors were analyzed and PI equation was built using Cox regression model. The prognostic index (PI) of patients was calculated on basis of the multivariate analysis. According to PI values, patients were classified into 4 different risk groups. The survival curves of each group were obtained. Results :Single factors analysis showed that age, T stage, N stage, M stage, clinical stage, invasion of skull base, cervi- cal lymph nodes metastasis and radiotherapy doses were prognostic factors; Multivariate analysis re- vealed that N stage, M stage, clinical stage and having chemotherapy or not were independent factors for overall survival. Conclusions :The N stage, M stage, clinical stages as well as performance of chemotherapy or not are the important prognostic factors of NPC. PI value will be very useful in predieting patients' prognosis and may provide the valuable information for physicians to give stratified or individualized treatment regimen.