Objective To investigate the appl ication of anti-rotation screw after dynamic hi p screw (DHS) in treatment of intertrochanteric fracture. Methods Between April 2006 and January 2010, 22 cases of intertrochanteric fractures underwent DHS fixation operation with an anti-rotation screw, including 15 males and 7 females with an average ageof 66.3 years (range, 54-83 years). Fractures were caused by sl ipping in 16 cases, traffic accident in 5 cases, and fall ing from height in 1 case. All cases showed closed fractures, including 13 cases in the left and 9 cases in the right. Eighteen cases were simple intertrochanteric fracture, 4 cases were intertrochanteric fractures compl icated with Colles fractures. According to Evans classification standard, there were 14 cases of type I, 6 cases of type II, 1 case of type III, and 1 case of type IV. The time from wound to operation was 3-7 days (mean, 4.5 days). Results The operation time ranged from 51-95 minutes (mean, 72 minutes). The intraoperative blood loss was 150-350 mL (mean, 270 mL). The hospital ization days were 12-35 days (mean, 16.8 days). Primary heal ing was observed in all cases. All cases were followed up 6-17 months (mean, 14 months). Union of fracture was observed at 12-16 weeks (mean, 13.6 weeks); no fracture or internal fixation loosening occurred. According to HUANG Gongyi’s standard of efficacy assessment, the results were excellent in 19 cases and good in 3 cases. Conclusion Appl ication of an anti-rotation screw can help to improve the strength of the DHS for the internal fixation of intertrochanteric fracture, especially the anti-rotation abil ity, which does not increase the operation time obviously.