Objective To evaluate the treatment results of LCP and locked intramedullary nailing for tibial diaphysis fractures.MethodsFrom October 2003 to April 2006, 55 patients with tibial diaphysis fractures ( 58 fractures) were treated. Of them there were 39 males and 16 females with an average of 39 years years ( 14 to 62 years). The fractures were on the left side in 27 patients and on the right side in 31 patients (3 patients had bilateral involvement). Thirtyfour fractures were treated by intramedullary nailing (intramedullary nailing group) and 24 fractures by LCP fixation (LCP group). The average disease course was 3 days (intramedullary nailing group) and 3.1 days(LCP group). The operation time, the range of motion of knee and ankle joints, fracturehealing time, and complications were evaluated. Results The patients were followed up 8-26 months(13 months on average). The operation time was 84.0±9.2 min (intramedullary nailing group) and 69.0±8.4 min (LCPgroup)； the average cost in hospital was￥19 297.78 in the intramedullary nailing group and ￥14 116.55 in the LCP group respectively, showing significant differences(P＜0.05). The flexion and extension of knee joint was 139.0±3.7° and 4.0±0.7° in intramedullary nailing group and 149.0±4.2° and 0±0.4° in LCP group, showing no significant difference(Pgt;0.05). The doral flexion and plantar flexion of ankle joint were 13.0±1.7° and 41.0±2.6° in intramedullary nailing group, and 10.0±1.4° and 44.0±2.3° in LCP group, showing nosignificant differences(Pgt;0.05). The mean healing time was 3.3 months in intramedullary nailing group, and 3.1 months in LCP group. Length discrepancy occurred in 1 case (2.5 cm), delayed union in 1 case and nailing endtrouble in 3 cases in intramedullary nailing group; moreover rotation deformityoccurred 1 case and anterior knee pain occurred in 6 cases(17.1%). One angulation and open fracture developed osteomyelitis in 1 case 1 week postoperatively and angulation deformity occurred in 1 case of distalthird tibial fractures in LCP group. Conclusion LCP and locked intramedullary nailing can achieve satisfactory results in treating tibial diaphysis fracture LCP has advantages in less complication, operation time and cost in hospital.