The purpose of this study is to evaluate biomechanical stability of Korean Ilizarov fixator before clinical application. We measured the ultimate tensile load and stiffness of Ilizarov smooth wire and olive wire, bending stiffness of half-pin, ultimate compressive load and stiffness of Ilizarov ring using Instron 1331. Four types of Ilizarov assembly were tested for measuring stiffness of axial compression, anteroposterior bending, and lateral bending. There were group I fixed with only smooth wires; group II with only olive wires; group III with wires and half-pins; and group IV with only half-pins. The results of Korean Ilizarov apparatus were compared to those of American Ilizarov apparatus using unpaired t-test. The ultimate tensile strength of Korean smooth wire was greater than that of American wire. The ultimate tensile strength of Korean olive wire was lower than that of American wire. There was no significant difference of stiffness of axial compression, anteroposterior bending, and lateral bending between American and Korean apparatus. There was no significant difference of axial compression stiffness and bending stiffness between group III and group IV. In conclusion, Korean Ilizarov apparatus can be used with good stability for treatment of fracture, internal bone transport, and limb lengthening according to this biomechanical study.