The present invention provides demineralized bone fibers exhibiting optimal handling properties (e.g., high moldability and low elastic modulus) and biological activities (e.g., osteoinductivity) as well as non-demineralized bone fibers useful for preparing the demineralized bone fibers. A well-controlled demineralization process for preparing the demineralized bone of fibers is also provided. Products comprising the demineralized bone fibers and uses thereof are further provided.