Objective　 To evaluate the effects of OsteoMed M3 titanium plate and screws on the initial stability of cervical vertebrae after expansive unilateral open-door laminoplasty.　Methods　OsteoMed M3 plate and screws and silk ligation were used for an simulated expansive unilateral open-door laminoplasty in six fresh human cervical spine specimens respectively，and fatigue experiment were measured in positions of flexion and extension on three-dimension motional stability test. The cessation of testing would be and the incidence of thread rupture and of loosening of thread and plate and screws were recorded.　Results　Partial rupture of joint capsule and easy move of the hinge side were seen in all of the specimens in the silk ligation. It were easily seen that rupture of joint capsule and cast of silk thread and reclose of the opened laminate as clinical widely used device for suture of joint capsule. There was no trauma on joint capsule in the OsteoMed M3 plate and screws, and no plate and screw loosening and rupturing and no reclose of the opened laminate. Conclusions　Unilateral open-door laminoplasty using OsteoMed M3 titanium plate and screws fixation is good for posterior cervical surgery because of its biomechanical advantage of maintaining signi?cant stabilization of the spine.