The principle of treatment of type 2, 3 odontoid process fracture is controversial. The debate is in regard to which is effective between conservative treatment and surgery. We enrolled 41 patients with type 2, 3 odontoid process fracture from January 2007 to December 2011 at Chosun University Hospital. Patients in Group I (GI) received a halo vest and those in Group II (GII) underwent surgery by ant. screw fixation. The bone fusion was classified according to stable bone union, fibrous union, and unstable non-union. Patients in GI received halo vest for a mean period of 4.9 months and those in GII received a neck collar for a mean period of 3.8 months. Tweleve patients in GI and 17 patients in GII had stable bone union. Three patients in GI and two patients in GII had fibrous union. Five patients in GI and two patients in GII had non-union. The halo vest was a good conservative treatment for type 2, 3 odontoid process fracture : however, low bone fusion rate is a problem in particularly old age. However, ant. screw fixation is a better treatment in regard to short surgical time, short fusion time, and high bone fusion rate.