The aim of this study is comparing of two prosthesis include short-stem and long stem. 70 cases of that refer to Sina hospital, Tehran, Iran due to femoral neck fracture will participate in each groups. The first we perform preparation before operation, for example, lab test, blood group, blood reserve, cardiology and analgesic consultation. After obtaining written informed consent for the surgery, patients will be randomly assigned in study groups. The Patients will be visited at the weeks 2 and 6 and months 3, 6 and 12 after surgery. Early complications include wound infection, early failure and late complications include avascular necrosis, loss of fixation, bread Union will be assessed. The frequency of treatment to track effects of setup time, setup quality time union attain acceptable levels of pain relief, patient satisfaction with the surgery will be measured. Clinical outcome and patients satisfaction will be evaluated with Harris Hip Score and SF-12, respectively.