Objective To investigate the clinical characteristics of unstable pelvic fractures and to find out an alternative for the treatment. Methods From October 2000 to June 2004, fifty-six patients with unstable pelvic fractures were treated by open reduction and pelvic-reconstructed plate fixation to recover the anatomical structure of pelvis and acetabulum. According to Tile classification, 33 cases were type B (15 cases were Tile B1, 11 cases were Tile B2, 7 cases were Tile B3); 23 cases were type C (10 cases were Tile C1, 8 cases were Tile C2, 5 cases were Tile C3). Results The 56 cases were followed up 12 to 68 months(26 months in average).All cases with fractures got healed during 3 to 6 mouths. According to the Majeed evaluation, 40 cases were excellent, 11 cases were good, 4 cases were fair, and only one case was a failure. The rate of excellency and goodness was 91.07%.The pelvic abnormity was rectified; partial patients felt light pain in iliac scar. Conclusion The choice of the proper operative approach and pelvic-reconstructed plate fixation by allowingfor fracture classification is a good and dependable means for treating unstablepelvic fractures.