To analyze the reasons and related factors of failures in the treatment of intertrochanteric fracture with dynamic hip screw (DHS) and to increase the therapeutic level of intertrochanteric fracture.All the 78 cases of intertrochanteric fractures were treated with dynamic hip screws from Dec. 1998 to Dec. 2007 included 42 males and 36 females with an average age of 62 years old ranging from 26 to 85 years. The disease course was from 1 to 49 hours (means 4 hours). According to Evans-Jensen classification of intertrochanteric fracture, 4 cases were type IA, 24 cases were type IB, 13 cases were type IIA, 22 cases were type IIB, 11 cases were type III, 4 cases were type IV. The fracture were fixed with dynamic hip screws following AO operative standard. To analyze the reasons and related factors of the 12 failed cases involving femur head and neck cut-off, tail pin exit, coxa vara, screw loosening, compress screw slip out of the tube, fracture displacement, respectively.All the cases were followed up for 13 months to 7 years with an average of 36 months, 12 cases were failed including 4 cases of femur head and neck cut-off, 1 case of coax vara, 2 cases of compress screw slip out of the plate tube, 2 cases of screws loosening, 2 cases of tail pin displacement 1 case of great trochanter fracture displacement.For intertrochanteric fracture, to interfix with dynamic hip screw is an effective method, the choice of indication, the type of fracture, the bone mineral density and the manipulative technique affect the results.