Objective：To explore the procedures and clinical outcomes of retroperitoneal partial nephrectomy for early malignant renal tumors. Methods: A total of 21 patients (19 men and 2 women, with a mean age of 49 years) with early malignant renal tumors were subjected to retroperitoneal partial nephrectomy using ultrasound knife and electron microscopy. The 21 patients included 17 with clear cell renal carcinoma, 3 with granule cell renal carcinoma, and 1 with oxyphil cell renal carcinoma. The mean diameter of the tumors was (2.8±0.8) cm. Results: All the 21 cases underwent successful retroperitoneal partial nephrectomy without conversion to open operation. Mean surgical time was (105±15) min and mean blood loss was (120±22) ml. Four patients had a mean blood transfusion of 400 ml. One patient had urine leakage, with drainage volume of 200300 ml; the drainage was stopped 15 days after operation when the drainage was less than 20 ml. The mean postoperative hospital stay was (9±2) days (717 days). No patients had local recurrence during a mean follow up of (20±4) months. Conclusion: Laparoscopic partial nephrectomy is feasible and safe.