Aim To seek the fixative relation between the pedicular Screw and the verterbral bodies and to furnish the basis of the improve for pedicular screw. Methods: the five not alike pedicular screw were evaluted With three dimensional limited element method. The pullout test and boundary surface stree measure were taken on the specimens of 9 cadaverice thareco Lumbar Result:the pullout power and boundary surface shearing stress of RF. UT, steffee, Dick, et al, were remarkabl difefrent(p<0.01) It was explain for heinfluence factors of the pedicular screw fixation were the shape,screw parameter, bone density and tightening up pitching moment. Conclusion: It was nessesery to increase the external diameter. deepen and the Length of pedicular screw according to the differece patients.