Objective To assess the factors affecting survival of malignant pheochromocytoma/malignant paraganglioma.Methods The clinical data of 85 malignant pheochromocytoma/malignant paraganglioma patients were analyzed retrospectively.All the patients were followed up,the duration from 2 months to 283 months,the median time was 48 months.The overall survivals of 5 years and 10 years were calculated.The possible affecting factors,such as gender,age,tumor function,metastatic sites,metastatic fields,incipience or recurrence,the time to recur,were analyzed.Survival differences between groups were compared with the log rank test.Multivariate analysis was performed by using Cox regression analysis to detect variables independently associated with survival.All P values were 2 tailed with P < 0.05 considered statistically significant.All statistical analysis was done by SPSS 17.0 software package.Results The overall median survival time was 62 months,5-year survival rate was 44.7%,10-year survival rate was 11.8%.Gender (P =0.649),age (P =0.228),incipience or recurrence (P =0.217) had no significant effect on the survival time.Significance was found in tumor function (P =0.034),metastatic sites,metastatic fields (P =0.009),the time to recur (P =0.003).The median survival time of patients with nonfunctioning tumor and functioning tumor was 90 months and 37 months.The median survival time of patients with multiple system metastases and single system metastasis was 37 months and 117 months.For the patients with single system invaded,there were 15 cases (26.8%) of bone metastasis,10 cases (17.9%) of lymph node metastasis,8 (14.3%) of liver metastasis,7 (12.5%) of lung metastasis,6 (10.7%) of renal metastasis,6 (10.7%) of intestine metastasis and 4 (7.1%) of brain metastasis.The median survival time was 110,77,28,14,26,8 and 19 months.The median survival time of patients with lung,liver,intestine metastasis were shorter than the other patients (P < 0.05).Fifty-five patients were found recurrence after operation,recurrent time was from 4 to 65 months,and the median time was 22 months.The survival time of patients with recurrence within 2 years was shorter than patients above 2 years (P =0.003).Conclusions The prognosis of malignant pheochromocytoma/malignant paraganglioma is poor.Gender,age,incipience or recurrence could not affect the overall survival time.The survival time has relationship with the function of tumor,metastatic field,metastatic sites and time to recurrence.The patients with nonfunctioning tumor have longer survival time than those with functioning tumors.The survival time of patients with single system invaded is longer than ones with multiple systems invaded.The common metastatic sites are bone,lymph node,liver,lung,kidney,intestine and brain.Patients with intestine metastasis have worst prognosis.The patients with only bone and lymph node metastasis have best prognosis.Patients with recurrence above 2 years have a better prognosis than those within 2 years. Key words: Pheochromocytoma; Malignant; Prognosis; Factor analysis, statistical; Kaplan-Meiers estimate