Open fracture characteristically has higher chances of infection and sof tissue damage in comparison with closed fracture. In spite of the development of operation methods and antibiotics, complications such as infection, nonunion, delayed union, and joint stiffness are continuously confronted as problems in the field of orthopedics. Different methods of treatment have been advocated as regards the care of the open wound and the method of stabilization of the fracture fragments. Therefore a comparative analysis of the type of open fracture and the bone union time according to the initial treatment methods was made from 47 cases over the age of 20, who were followed up until bone union developed among the inpatients who were treated for open fracture of tibia in the period of 7 years from January, 1982 to December, 1988, and the results are as follows: 1. The highest incidence of fractures was encountered in 3rd decade(34%) and male to female ratio was 6:l. 2. The most common cause of fractures was traffic accident(76.6%). 3. The most common level of fracture was in mid one-third and the bone union time was longest in mid one-third. 4. The bone union time was longer, and the rate of complication was greater in order of type 1, 2 & 3 according to Gustilo's classification. 5. The good result was obtained in type 1 fractures, by using the closed reduction & cast immobilization and pin & plaster method; in type 2, the bone union time was shortest in the cases of pin & plater method; in type 3, the bone union time was shortest in the cases of closed reduction or open, reduction & external fixation. 6. Bone union was obtained in all cases of delayed union and nonunion and the bone union time was shortest in cases treated with plate & bone graft.