Abstract： Objective To explore the stress changes of C7/T1 intervertebral space pre-and post C5/6 discectomy and artificial disc replacement.Method Eleven healthy adult fresh muhisegmental cadaveric cervical spine segments were utilized in this investigation and biomechanically evaluated under the following C5/6 conditions:intact spine,discectomy,and Bryan Disc prosthesis implantation.The load,of neutrality and pure moments of axial,flexion,extension,and lateral bending were applied on each group.The stress changes of the inferior (C7/T1)interverlebral space was detected by modified cyclo-shaped miniature transducer.Result Under axial,anteflexion,and lateral bending loading,the discectomy indicated a significant increase in the stress of the inferiorer(C7/T1)intervertebral space,compared to intact condition and CADR(P＜0.05).Under extension loading,the discectomy indicated an increase in the stress of the inferiorer(C7/T1)intervertebral space,compared to intact condition(P＞0.05).Under axial,flexion,extension and lateral bending loading,the Bryan Disc prosthesis implantation indicate minor increase of the stress in the inferior(C7/T1)intervertebral space to intact condition(P＞0.05).Conclusion There was no difference between the C5/6 ADR and intact spine group.The discectomy of the Cs/6 can increase the stress of the C7/T1 intervertebral spaoe.