Abstract: Objective: To summarize the technique and effect of the open reduction and internal fixation surgical operation for trimalleolar fractures.Methods: The arc-shaped inside incision was done to expose the medial malleolus and posterior malleolus.Through a straight incision in trailing edge of fibula,fractures of fibula and lateral malleolus were showed in surgery vision.Then fracture restoration and internal fixation were carried out by the sequence of posterior malleolus,medial malleolus,lateral malleolus and distal tibiofibular syndesmosis.Results: According to the criterion of AOFAS,30 patients were classified in excellent,17 in good,5 in fair.The total percentage of excellent or good effects in all of 52 cases were 90.4% after a follow-up period of 12-36 weeks.Fractures were healed up in average 14 weeks.Conclusions: For these patients with pronation and supination external rotation trimalleolar fractures,the ankles function of fractures could have effective recovered through open restoration,steady fixation and restoring the anatomy relations of the ankle joints.