Abstract: Objective: To evaluate the diagnosis and treatment of the renal carcinosarcoma. Methods: Three cases of renal carcinosarcoma were reviewed. Results: Three cases underwent radical nephrectomy. The carcinosarcoma were proved postoperatively in three cases by pathology. Three patients died of the disease 10 months 6 months 5 months after operation. Conclusions: The renal carcinosarcoma is rare and is difficult to be diagnosed preoperatively and immunohistochemistry are helpful for its diagnosis.