[Objective]To evaluate the effects of transpedicular internal fixation system for occipitocervical fusion.[Method]From Jan.2004 to Jan.2007,occipitocervical fusion was performed in 21 patients(12 male,9 female,mean age 45.3 years) with transpedicular internal fixation system(Sofamor Danek Company).There were 14 with upper cervical tumor,3 with cervical congenital malformation and 4 with dens axis fracture combined with atlantoaxial dislocation.The clinical outcomes were investigated by clinical observations,radiologic studies and statistical analysis.[Result]All the patients were followed up for 6 to 40 months with an average of 21 months.The result of X-ray showed that bony fusion was successful in 16 patients at 3 months and 5 patients at 6 months of follow-ups.There was no deterioration of spinal cord injury.The JOA scores of neurofunction increased from 5-17 points(mean 12.6 points) to 8-17 points(mean 15.8 points),with the improvement of 72%.All patients were partly limited in rotation movement.Seventeen patients had a rotatain of 100?,three was 80?,and one was 50?.[Conclusion]Transpedicular internal fixation system has multiaxial screw of three-column fixation and plastic rods,which offers strong fixation and good fusion.It can also benefit the maintenance of cervical curve.It is an effective and reliable method for reconstruction of upper cervical stability.