Bone is a living composite material consisting of inorganic minerals, organic proteins, and water, which approximately account for 60%, 30% and 10% of bone mass, respec-tively. In the reported experimental studies on bone mechanical properties, attention has been focused on the effect of inorganic minerals while the role of organic proteins and water has been ignored. This neglect may explain why the existing bone mechanical models are not accurate. Furthermore, a reliable experimental protocol for the study of bone compositions and their effects on mechanical properties has not yet been estab-lished. In this thesis, the combined effect of organic proteins and water was studied by developing a novel experimental protocol. First, to reduce the effect of bone anisotropy, a unique technique was designed for the fabrication of bone specimens; Second, for the analysis of bone inorganic and organic compositions, a new ashing procedure was developed; Third, the effects of bone inorganic and organic contents on bone mechanical properties were studied by statistical analyses. The obtained results showed that there is a close correlation between bone organic content and bone stiffness.