To investigate the effectiveness of T-locking plate in treating medial clavicle fracture so as to find out a therapy with safety and stabil ity. Methods Between October 2006 and January 2009, 13 patients with medial clavicle fracture were treated with open reduction and T-locking plate fixation. There were 9 males and 4 females, aged 18-68 years (mean, 47 years), including 7 cases of traffic accident injury, 4 cases of fall ing injury from height, and 2 cases of heavy object hit injury. The locations were left side in 5 cases and right side in 8 cases. All cases were closed fracture. The disease duration was 1 hour to 14 days. Results All incisions healed by first intention after operation. The X-ray films showed good reduction of fracture and internal fixation. All the 13 patients were followed up 12-18 months (mean, 15 months). The average fracture heal ing duration was 8 weeks (range, 6-12 weeks). No compl ication of infection, nerve or blood vessel injury, hemopneumothorax, or internal fixation loosening or failure occurred. The anatomical medial clavicle structure as well asappearances and functions were restored. According to Rockwood’s score method, the results were excellent in 11 cases and good in 2 cases. Conclusion The internal fixation of T-locking plate in treating medial clavicle fracture has the advantages of good stabil ity and low risk. Besides, the patients can do functional exercises early and the shoulder joint function can be improved in great degree.