Objective:To evaluate the clinical effect for the treatment of irreducible atlantoaxial dislocation by video-assisted anterior release through anterior upper cervical procedure.Methods:Twenty-one patients,there were 13 males and 8 females with the mean age 31.6 ranging from 16 to 48 years old.The interval between the onset of the symptoms and the diagnosis was averaging 16 months ranging from 6 to 48 months.The type of diseases including:8 late odontoid fracture,7 with osodontoideum,5 relaxation of trnsverse ligament of atlas,1 selfunion of occipital-atlantal junction with short odontoid.The preoperative JOA score 9.6.The surgical methods:soft (or bone) tissue released between C1 and C2,skull traction and posterior surgery after one week.