Objective To evaluate the clinical significance of anatomic reduction and internal fixation of posterior malleolar fracture in ankle fracture surgical treatment. Methods Fifty-four patients with posterior malleolar fracture were treated with anatomic reduction and internal fixation from March 2005 to June 2010. The patients groups consisted of 36 males and 18 females. According to CT scan classification,the group was made up of 36 type Ⅰ cases, 10 type Ⅱ and 8 type Ⅲ cases. All patients were evaluated with modified Baird-Jackson scoring system. The relationship between final result and fracture pattern , fixation methods, the time of exercise initiation fitted operation were analyzed respectively. Results The followedup period varied from 6 months to 36 months, with an average of 18 months. The number of patients whose result was excellent, good, fair and poor was respective 29,18 ,5 and 2. The total percent age of good to excellent clinical result was 87. 03%. There were 4 patients who had only slight pain after long time walking ,the remainder patients were completed with no pain. Conclusion Operative treatment may provide satisfactory fracture anatomic reduction and internal fixation for posterior malleolar fracture. Correct fracture pattern estimation and proper internal fixation are important to achieve and improve reduction quality, and to ameliorate better long term results.