Cartilaginous lines at the time of postnatal period in the C2 bone may be used for the dividing of C2 vertebra in the classification of C2 fractures. According to this classification, axis (C2) fractures are classified into three main groups based on a postnatal developmental model of C2. Eighteen cases of C2 fractures are classified according to this classification. They were divided into three main groups as the odontoid fractures, body fractures and neural arch fractures. Five patients had odontoid process fractures, 5 had body fractures, 2 had pedicle fractures, and 6 had neural arch fractures. Neural arch fractures consist of pars interarticularis fractures (3 cases) and others (3 cases with combined lamina and spinous process fractures). This classification is based mainly on the location of the fracture in the portion of the postnatal developmental segments. We suggest the use of a classification based on a postnatal development model. The use of this model can make classification of C2 fractures more systematic and more understandable.