Zhen xx,male ,49 years old,,traumatic,atlantoaxial subluxxation .On July 26th 2005,the patient had a operation of posterior atlantoaxial bilateral Mager and Titanium mesh fixation and fusion .postoperative CT and Three-dimensional CT shows bilateral ucss screm all passed the Atlan toaxial joint ,there is plenty of bone around the screw ,After operation Atlantoaxial dislocation obtain anatomic reduction ,this operation has high skill requirement on the operator ,the operation is of high risic,however ,the procedure not only obtains the anatmic reduction of fracture ,but also enable access to the stability of the recons truction of the spine and full decompression of spinal canal and able to retain the maximum degree of activity of the cervical spine.Aepresent ,our section had done such cases for 100,and the surgery level leads that of the nation.