Abstract: Objective:To analyze the impact of endophytic extent of renal tumor on the perioperative outcomes after partial ne -phrectomy and evaluate the long-term therapeutic effect of early renal cancer. Methods:A retrospective review was performed for 157 patients who underwent partial nephrectomy of T1N0M0 kidney cancer in Tianjin Medical University Cancer Institute and Hospital be -tween January 2011 and December 2013. The patients were classified into two groups according to the distance of the tumor margin to the collective system or renal sinus fat: group A, < 1 cm; and group B,≥1 cm. The perioperative outcomes and pathologic types in the two groups were summarized and analyzed. The postoperative complications were recorded and followed up. Results:No statistically significant differences were found in the patients' gender, age, tumor size, recidivist status of Chung Chi, estimated blood loss, postoper -ative hospitalization time, and pathological types between the two groups ( P>0.05). The warm ischemia time and operation time were significantly longer in group A than in group B ( P=0.001; P=0.033). Postoperative complications occurred in 10patients. No local tu-mor recurrence or metastasis was observed in the patients during a median follow-up of 18months.Conclusion: The distance between the tumor margin and the collective system reflects the complexity of partial nephrectomy, which is associated with the warm ischemia time and operation time. Partial nephrectomy is safe and effective. This procedure has low complications and good survival.