Objective The purpose of this experimental study was to find the important factors affecting the stability of cannulated cancellous screws in femoral head and provide experimental basis in clinical use on femoral neck fracture using internal fixation with cannulated cancellous screws.Methods 31 femoral heads were from the patients of femoral neck fracture,then cannulated cancellous screws were embedded into them by the method for the treatment of femoral neck fracture.We recorded the ages of the patients,the diameters of the femoral heads,the BMDs of the femoral head,the distances from the tips of the screws to the articular surfaces of femoral heads.we fixed up femoral head and screw extremity into the mechanical experimental apparatus and carried out the tests.We got the stress-strain curves and the maximal pullout stresses of the screws.The data were analysed by multiple regression of SPSS for windows 11.5.Results The difference of the femoral head's BMDs and the depths of the screws which were embedded into the femoral heads brought about the difference of the maximal pullout stresses.By multiple regression,we found that the maximal pullout stresses of the screws were correlated with the femoral head's BMDs and the distances from the tips of the screws to the articular surfaces of femoral heads,the maximal stresses positively were correlated with the fore(P=0.002) and negatively correlated with the latter(P=0).Conclusions We should choose the higher BMD's patients of femoral neck fracture to treat them with cannulated cancellous screws and embed cannulated screws into the special depth of femoral head.