Objective To compare the biomechanical properties of two different fixation. Methods Fourteen cadaver femure were used in the study. complete fractures of femoral necks were induced with Pauwel＇s angle more than 70 degrees and divided into two groups rendomly which were fixed by cannulated screw fixation with two different geometric contiguration of positive or negative triangle respectively. The biomechanical properties of two different fixation were evaluated. Results Main mechanical properties in negative triangle group such as tensile strain compressive strain displacement of femoral head (except horizontal displacement) axial and lateral rigidity ultimate load and yielding limit were significantly better than in positive triangle group (p<0.05). Conclusion Through biomechamal test we concluded that negative triangular internal fixation were better conformed to biomechanical demanded of fixation of femoral neck fracture than positive triangle group.