To compare the cutting and reversing property of there different diameter conicalpulling-screws. Methods: In the material experimental machine, the conical pulling-screws withtheir respective diameter of 4mm, 5mm, 6mm which had been deeply frozen from fresh cadavericfemur shaft of young adult, examine the cutting intensity and rigidity property of the smooth partsof screw and the saw tooth parts seperately, then the reversing and destorying. Rusultf The cuttingintensity of the smooth part of screws were respectively 526N, 1034N, 1459N, and of the saw-toothpart of screws were respectively 290N, 505N, 931N. There marked differences in the cutting intensityand rigidity between the smooth of screw were marked and the saw-tooth part, which are of thesame diameter. The differences were also significant with different diameters. The maximummoments of force among the 4mm-diameter, 5mm-diameter, 6mm-diameter pulling-screw were0.64Nm, 1.59Nm, 2.10Nm respectively.While the moments of force of pulling-screws with differentdiameters were siguificant diferent. Conclusiont The biomechanical property of the pulling-screwswith same diameters is different, and the property of those with different diameter was slgnificantdifferent.