Objective To study the safety of tumorectomy combined with intraoperative radiotherapy in the treatment of retroperitoneal tumor.Methods The patients diagnosed as retroperitoneal tumor by abdominal CT and/or MRI since July 2009 to July 2010 were chosen as the objects with the exclusion of the following conditions: 1) pathologically confirmed lymphoma,hematopoietic system tumor,and urogenital system tumor;2) tumor was found to involve a wide area or with multiple lesions in retroperitoneal space as shown by preoperative CT and/or MRI.Sixty-two patients were found to have localized tumor,and they were divided into two groups: combined treatment group(n=30) and control group(n=32).The patients in combined treatment group underwent total excision of the tumor followed by intraoperative radiotherapy;in control group the patients underwent tumorectomy only.The changes in pre-and post-operative white blood cell count,recovery of gastrointestinal function,wound healing and incidence of complications were compared between the two groups.Results There was no difference between the two groups in pre-and post-operative white blood cell counting,recovery of gastrointestinal function,wound healing and incidence of complications(P > 0.05).Conclusion Tumorectomy combined with intraoparative radiotherapy in the treatment of retroperitoneal tumor is safe and entailing no higher incidence of complications.