To present and share our robot-assisted partial nephrectomy (RAPN) experience for renal mass > 15cm.We retrospectively analyzed the clinical data of a case who underwent RAPN for renal mass > 15 cm in size at our center in June 2015.The case was a 34 yrs female found of having a large right kidney tumor in routine checkup one month before surgery.MRI showed an exophytic 8 x 5 x 15 cm mass at the lower pole of right kidney.Angiomyolipoma was the diagnosis.RAPN had been performed in transperitoneal approach.Surgical technique,warm ischemia time (WIT), oncologic, and pathologic data were analyzed.