Abstract: Objective:To retrospectively analyze related factors of subtype transformation and to identify prognostic factors for pa-tients with retroperitoneal liposarcoma (RPLS).Methods:This study retrospectively analyzed the clinical data of 92patients with RPLS, which were confirmed by postoperative pathology from July1997to October 2014in Henan Provincial Tumor Hospital. Related studies were reviewed, and the prognoses were followed up. The factors may affect subtype transformation or prognoses were applied to the statistical analysis. Results:A total of 74patients with RPLS were included according to the recruiting standard. The 5-year survival rate was 48. 65% . Lobulated tumors (P=0. 013 ) were the correlative factors that influenced subtype transformation. The Log- rank test showed that the age at diagnosis (P=0. 045 ), multi-visceral resection (P=0. 042 ), tumor necrosis ( P<0. 001 ), subtype transformation (P< 0. 001 ), and malignant level of pathological subtypes of the first operation (P<0. 001 ) influenced overall survival. Multivariate Cox re -gression analysis showed that tumor necrosis and the malignant level of the initial histological grade were independent factors of over -all survival. Conclusion: Lobulated tumors are likely to transform the subtype. The prognosis of patients with RPLS is correlated with multi-visceral resection, tumors necrosis, subtype transformation, and the malignant level of pathological subtypes of the first opera-tion. Multi-visceral resection could not improve the 5-year survival rate of RPLS, and adjuvant therapy could not improve the prognosis.