This paper investigates a design optimization for "Bone Plate System" which can directly fix human bones fractured. The active trauma system consists of several shaped bone plates and implant screws for fixation of fractured human bones with various manual instruments allowing to handle them. The material corresponds to titanium because it was well known as harmless material when being inserted into human body. This system has to be suitably rigid as well as manually bended in orthopedic surgery operations. Then bone plates have to be designed with suitable shapes. In order to verify whether bone plates were well designed, a series of bending tests. However optimized shapes of bone plates have to be determined before unnecessary a number of bending tests. For this purpose FEM(Finite Elements Method) was applied during design process which allows us to investigate the bending strengths of bone plates. Based on FEM results, dimensions of bone plates were optimized in order to be suitably rigid without actual bending tests.
