Objective To explore the clinical effect of operation fixation in hip dislocation with acetabular posterior wall fracture and the influencing factors on prognosis.Methods 35 cases diagnosed as hip dislocation with acetabular posterior wall fracture were treated with reconstruction plate internal fixation through K-L approach.Results 35 cases were followed up for 2 years ～ 5 years and 4 months.Modified Merle d' Aubingne-Postel scoring system was used for clinical assessing: excellent in 16 cases,good in 12,fair in 4,and poor in 3.Matta imaging ratings: excellent in 13 cases,good in 16,fair in 5,and poor in 1.Clinical results and X-ray ratings was significantly positive correlation.The patients with age ≥55y or the reduction time ≥12h or complex type fracture showed a significant decrease in the clinical scoring.Conclusions Instantaneous diagnosis and reduction,restoration of acetabular continuity and stability are the keys of successful treatment.Patient age,reduction time and fracture type are important factors for the prognosis.