Abstract： Objective To explore the safety, feasibility and superiority of minimally invasive percutaneous nephrolithotomy(MPCNL) in treating complicated renal calculi. Methods 106 patients suffering from complicated renal calculi were treated with 121 MPCNL. Results 89 cases underwent MPCNL with single tract ,29 cases with two tracts and 3 cases with three tracts in 106 patients. Renal calculi were cleared completely in 90 patients with one-staged MPCNL, 11 patients with two-staged MPCNL but 5 patients had residual renal calculi and treated with extracorporal shock wave lithotripsy(ESWL) afterwards. 92. 6% calculi free-rate was achieved. Average operation time was 91 minutes,bleeding ranged from 100 to 900 ml and 5 patients accepted 200～400 ml blood. There were no severe complications in all patients. Conclusion MPCNL is a minmally invasive, safe and effective operation for comlicated renal calculi.