Abstract： Objective To report the results of anatomical study and clinical application of C2 pedicle screws combined with C1 lateral mass or occipital screws used for posterior eraniovertebral junction internal fixation. Methods Four cadaver specimens of head and neck fixed by formalin were used for study of C2 pedicle and C1 lateral mass screw insertion,afterwards,CT scan was performed for evaluation of the position of the screws. From May 2004 to January 2007,C2 pedical-C1 lateral mass/occipital screws internal fixation was applied in 9 patients,including 4 male and 5 female,their age ranged from 12 to 68 years old.Fixation was performed for C1-C2 sublaxion due to various reasons in 6 patients, after transoral odontoidectomy due to basilar invagination in 1 patient,before transoral removal of clival chordoma in 2 patients. Among them,C2 pedieal-C1 lateral mass screws fixation technique was used in 4 patients,C2 pedical-occipital screws fixation technique in 5. Results It was necessary to directly expose the superointerior edge of the C2 pedieal,in order to localize the entry point of the screw in the posterior part of the isthmus and to justify the screw direction; direct exposure of the posterior midline of the C1 lateral mass helps localize the screw entry point and avoid injury of the vertebral artery. Among 9 patients,postoperative CT demonstrated 2 screws breakthrough of the cortical bone in 2 patients,without neural or vascular compression or injury; in the other patients,all the screws were appropriately positioned. Follow-up ranged from 4 to 32 months,clinical improvement was found in 8 patients ; only in one patient,the symptoms did not change postoperatively. Conclusion C2 pedical-C1 lateral mass/occipital screws can be used for posterior craniovertebral junction internal fixation safely and effectively.