Interlocking intramedullary nailing has been popularized by its many advantages in the fracture treatment of long bone compared with the other fixatives. The purpose of this paper was to evaluate the treatment results in the viewpoint of bone union, complication and functional outcomes of the interlocking intramedullary nailing between reamed and unlearned technique in the treatment of tibial shaft fractures. We reviewed 64 tibial shaft fracture that were treated at our hospital from May 1990 to February 1995 with interlorking intramedullary nailing that composed 36 reamed, and 28 unlearned cases. These included 33 open fractures and 34 closed fractures. There was no significant di florences in average prriod of radiologic union, complications and in the functional outcomes between the two treatment grovps(P<0.05). Unlearned interlocking intramedullary nailing in the tibial shaft fractures must be a goof treatment modality by its simplicity, shorter operation time, less probability in pulmonary and throrrlboembolic complications and less comprormised medullary blood supply, especially in patients with multiple trauma or open fractures.