Objective　To explore clinical efficiency of different surgical internal fixations on treating the unstable pelvic fracture according to the anatomic features of the pelvis.　Methods　65 cases suffering from the unstable pelvic fractures, were included in this study. Anterior approach, with the replacement and plate fixation of symphysis pubis or ramus of pubis, was performed for 31 cases of Tile B type fracture. 8 cases combined with ilium fracture among them were replaced and fixed through iliac fossa approach. As well, anterior approach also was used for fixing damaged anterior girdle of 34 cases of Tile C type fracture. However, the damaged posterior girdles were treated with the replacement and the posterior sacroiliac screw fixation under X-ray guide for 11 among 17 cases of sacral bone fracture or dislocation of sacroiliac joint, while, 4 cases treated with transiliac gudgeon fixation, 2 cases with tensile plates fixation between bilateral posterior iliac spine through posterior approach. For 9 cases of sacroiliac joint fracture and dislocation, 6 fixed with transdermal screw, and 3 with the plate. 8 cases combined with acetabulum fracture were fixed with the plate. Results　According to the index of Matta score, which analyzed the greatest distance of the pelvic fracture displacement under X-ray evaluation, 56 cases (86.1%) were excellent, with the shorter displaced distance of the less of 4mm, 5 cases(7.7%)  were fine, with the displaced distance of 4~10mm, 4 cases (6.2%) were better, with the displaced distance of 10~20mm, and no case was bad, with the greater displacement distance of 20 mm. Conclusions　It is important to select reasonable internal fixation proposal for treating the unstable pelvic fracture, according to the different fracture types and anatomic features of pelvis.