Objective:To investigate the effect and safety of the hi-channel in one-stage of minimally invasive pereutaneous nephrolithotomy (mPCNL) in management of complicated renal calculi, compared with single chan-nel in two-stage of mPCNL. Methods: 57 patients underwent mPCNL in treatment of complicated renal calculi were retrospectively reviewed. 31 eases in group A underwent bi-channel in one-stage of mPCNL;26 eases in group B underwent single channel in two-stage of mPCNL. Results= The mean bleeding in the group A was 146. 4 m1(75-262.5 ml), compared with the group B 154.3 ml(75-300 ml), there was no statistically difference between the two groups (P>0.05). The mean operation time in the group A was 88. 4 rain(65-136 min), compared with the group B 123.1 min(70-180 min), there was statistically difference between them(P<0.05). Compared of the clearance rate of stone in the group A 83.9 % (26/31) and B 57.8% (15/26), there was statistically difference be-tween them (P<0.05). Conclusions:According the treatment of complicated renal calculi, the bi-ehannel in one-stage of mPCNL has shorter operation time, higher clearanee rate of stone, compared with single channel in two-stage of mPCNL. The patients need less expenses and shorter time staying in hospital. It is an ideal method.