Abstract: Objective To explore the prognostic factors of patients with primary retroperitoneal tumor（PRT） treated by surgical re-section. Methods We retrospectively analyzed 80 patients with PRT treated in the First Affiliated Hospital of Guangxi Medical Uni-versity between June 2001 and June 2012.Survival and prognosis were analyzed using the Kaplan-Meier method，the Cox proportional hazard model and the log-rank test. Results All patients were followed up for a median of 40.4 months， and the 1-， 3-， and 5-year cumulative survival rates were 92.5%，73.1% and 67.5%.Median survival time was 67 months. Univariate analysis identified the fol-lowing significant predictors of survival（P<0.05）: surgical method，tumor size，tumor characteristics，mitotic counts of tumor cells，and invasion of adjacent organs.Multivariate analysis identified the following independent prognostic factors（P）:surgical method，tumor <0.05characteristics，mitotic counts of the tumor cells and invasion of adjacent organs. Conclusion Surgical resection is the most ef-fective treatment for PRT.Tumor characteristics， surgical method，invasion of adjacent organs and mitotic counts of tumor cells are the most important prognostic factors for PRT.

Key words:  Primary retroperitoneal neoplasms, Surgical resection, Survival rate, Prognosis, Regression analysis