Objective To explore the biomechanical stabil ity of ideal compression screw (I.CO.S.) for treatment of femoral neck fracture and to provide theoretical basis for choosing I.CO.S. in cl inical appl ication. Methods Thirty cadaveric human femurs were selected and divided randomly into experimental group (n=15) and control group (n=15), 15 in each group were divided equally into three sub-groups (n=5) again. The model of subcapital femoral neck fracture was made, then given anatomical reduction and fixed with I.CO.S. (experimental group) and general cannulated compression screw (control group) separately with three different configurations: two horizontal (parallel screws in superior aspect of femoral neck), two vertical (parallel screws in sagittal plane of femoral neck) and reverse triangle. The different biomechanical performances were evaluated through experimental stress analysis. Results In biomechanical stabil ity aspect: groups A, B, C was better than groups D, E, F in respect of horizontal displacement and yield load (P lt; 0.05); groups A, D was better than groups B, E in respect of the straining, horizontal displacement and yield load (P lt; 0.05); and there were not significant differences in all biomechanical indicators between group C and group F, and between group A and group C(P gt; 0.05). Conclusion I.CO.S. has the good biomechanical stabil ity for treatment of femoral neck fracture, which mayprovide basis for appl ication.