Objective:To investigate the safety and prognosis of partial nephrectomy (PN) in the treatment of highly malignant non-clear renal cell carcinoma (nccRCC).Methods:Clinical data of 47 patients with cT 1N 0M 0 high malignant nccRCC treated in Changhai Hospital from March 2016 to March 2022 were retrospectively analyzed. All patients received PN. There were 34(72.3%) males and 13(27.7%) females. The mean age was (53.5±15.0) years, and average BMI, was(23.7±3.4)kg/m 2.The maximum tumor diameter was (29.8±12.6) mm, and R. E.N.A.L. score was 7(5-9), with 37(78.7%) cases of T 1a and 10(21.3%) cases of T 1b. The mean estimated glomerular filtration rate (eGFR) before surgery was (96.3±25.5) ml/ (min·1.73m 2). All patients underwent PN, including 1 patient (2.1%) undergoing open surgery, 29 patients (61.7%) undergoing laparoscopic surgery, and 17 patients (36.2%) undergoing robotic surgery. There were a total of 22(46.8%) cases of papillary cell carcinoma(pRCC)type Ⅱ, 4(8.5%) cases of collecting duct carcinoma (cdRCC), 9(19.1%) cases of MiT family translocated renal cell carcinoma (tRCC), 5(10.6%) cases of mucoid tubular and spindle cell carcinoma (mtSCC)and 7(14.9%) cases of unclassified renal cell carcinoma (uRCC). The surgical conversion rate, positive margin rate, operative time, intraoperative blood loss, complications, and postoperative hospital stay were analyzed. Preoperative and postoperative eGFR were analyzed, and overall survival (OS) and cancer specific survival (CSS) were calculated. Results:All the operations were successfully completed. No radical operation or open operation was performed, with operation time of(100±60) min and intraoperative blood loss of(100±59) ml. There were no intraoperative complication and 1 case (2.1%) suffered from postoperative complication. Postoperative hospital stay were 5 (4-6) days. The mean eGFR after surgery was (86.5±27.1) ml/(min·1.73m 2), and the difference was statistically significant ( P=0.041). In this study, the mean follow-up time was (45.7±20.9)months, and no adjuvant therapy was used after surgery. During the follow-up period, 2 patients died, who all of them were kidney cancer-related death, and both OS and CSS were 95.7% (45/47). Conclusions:PN is safe, feasible and has a good prognosis in the treatment of high malignant T 1 nccRCC. For tumors with clear imaging boundaries and complete envelope, complete tumor resection is more likely, postoperative follow-up should be strict, and no remedial radical or systemic treatment was required.