Disclosed is a method for producing demineralized bone matrix with improvement of releasing bone morphogenetic protein by irradiating the demineralized bone matrix, the demineralized bone matrix produced by the producing method, a method for extracting bone morphogenetic protein using the demineralized bone matrix, and the bone morphogenetic protein extracted by the extracting method. The demineralized bone matrix produced according to the present invention and the bone morphogenetic protein extracted by using the demineralized bone matrix can be advantageously used in manufacturing bone restorative implants, bone growth accelerating compositions, and/or health aids or supplementary food products.