It is well known that the structures of the organisms give some important hints for the material development. To obtain a new idea on the optimum design of the material structures, the fore-wing of Allomyrina dichotoma was used and its mechanical properties and micro structures were investigated. As a result, the non-equiangular laminated structure and mechanical anisotropy of A. dichotoma fore-wing were made clear. The fracture processes of the fore-wing could be classified into two types, and their fracture mechanisms depended on the average lamination angle of chitin fiber layers. The bridging chitin fibers could not be observed in type I, while they were observed in type II. It was found that the fore-wing had the anisotropic tensile behavior, and using a parameter, η, the anisotropic tensile behavior could be represented. The results obtained here should be helpful for the optimum material design.
