Objective To analyze and evaluate the safety of partial nephrectomy(PN) for clinical T1b renal cell carcinoma.Methods From January 2008 to January 2011,a retrospective analysis was preformed for 84 patients with clinical T1b renal cell carcinoma underwent PN.The average maximal diameter was 4.9 cm(range 4.2-7.0 cm)by CT scan or MRI.Operation time,warm ischemia time,safety margin,blood loss,renal function change and local recurrence were analyzed.Results Eighty-four operations were completed successfully.Medianwarm chemia was 14 min (range 11 to 25 min).Median blood loss was 70 ml (range 30-200 min),no transfusion needed.The mean tumor maximal diameter was 5.0 cm(range 4.1-7.0 cm).The mean surgical margin was 3 mm(range 2-5 mm),no tumor cells.The median follow-up was 47 months(range 68-32 months),all the 84 patients survived without local recurrence.The serum creatinine levels after operation were the same as those before operation.Conclusions Partial nephrectomy (PN) is effective and safe for T1b renal cell carcinoma.Size,location,growth pattern,relation with the renal hilum are important related factors for successful operation.