Abstract: Objective To analyze the relationship between serum preoperative C-reactive protein (CPR) level and the prognosis of retroperitoneal malignant fibrous histiocytoma (MFH). Methods Clinical pathological and prognostic data about 50 patients with retroperitoneal MFH in Chinese PLA General Hospital from March 2000 to March 2015 were collected. According to the CRP level, patients were divided into high CRP group (n=19) and normal CRP group (n=31). The differences in clinicopathological features and prognosis between the two groups were analyzed. Results Univariate analysis showed that CRP level (χ²=5.911, P=0.015), operation method (χ²=16.811, P=0.000) and tumor stage (χ²=4.741, P=0.037) were related to prognosis. The multivariate analysis showed that CRP level (HR=4.865, P=0.003), operation method (HR=4.546, P=0.002) and tumor stage (HR=2.4, P=0.031) were independent prognostic factors for prognosis of MFH. Conclusion Retroperitoneal MFH patients with high serum CRP level have poor prognosis.