Objectives:To explore a clinical classification method of atlantoaxial dislocation and offer therapeutic regimen with strong guidance for the clinic.Methods:According to the etiopathogenesis,course of disease,and imaging,168 cases of C1 ~2 dislocation caused by different causes were grouped into 3 types and 4 subtypes:(1) Traction reduction type,which is abbreviated as the T type and is divided into T1 and T2 subtype because of different cause and course of disease.(2) Operation reduction type,which is abbreviated as the O type; (3)Irreducible type,which is Ⅰ type; We named this classification method mentioned above as TOI classification.Therapeutic regimen:type T1:applying traction or orthosis to treat for 8-10 weeks;type T2:traction reduction and fusing C1~ 2; type O:Transoralpharyngeal atlantoaxial solution an dposterior fixation; type Ⅰ:decompression and fixation in situ.According to clinical standard,JOA and SAC imaging standard to evaluate the curative effect.