Objective To evaluate the effect of self-designed antirotation reduction internal fixator(ARRIF) on treating different spine segment fracture.Methods From August 1999 to March 2003, 76 patients(48 males and 28 females, aged from 22 to 59 with an average of 34.1) with thoracolumbar fracture were operatively treated by ARRIF. The follow-up period ranged from 6 to 21 months(15 months in average). Classification according to injury segment: flexion compression racture 27 cases, burst fracture 42 cases, flexion distraction injury 3 cases, flexion revolving type fracture dislocation 2 cases, shear force type dislocation 2 cases. Classification according Frankel’s grade:A grade 16 cases, B grade 15 cases, C grade 27 cases, D grade 10 cases, E grade 8 cases.Operation duration, volume of bleeding, incidence postoperation complication and effect of reduction fixation were observed. Results The operation duration of ARRIF was 1.2 h in average, and there was about 200 ml volume of bleeding during operation. The nerve function showed one Frankel’s grade improvement after operation were as follows:A grade 8 cases(50%), B grade 11 cases (73.3%), C grade20 cases(74.1%), D grade 3 cases (30%); 2 Frankel’s E cases have no nerve function changes.The nerve function damage have no aggravation in all the patients,the postoperation Cobb’s angle was averagely corrected 22°. The horizontal displacement of dislocation vertebrae was averagely corrected 28% in sagittal plane, the statistical analysis had significant variance(Plt;0.01).ARRIF had no complications of the breakage of screws and rods. Conclusion ARRIF proves to be a valid internal fixator in reducing and fixing different thoracic lumbar segment spine fracture.