Dependence of the activity of monoamine oxidase-B (MAO-B) in different human bone marrow (BM) sections on death-coming prescription (DCP) and on age was investigated. It was established that the activity of MAO-B in BM cervical intumescence is an objective DCP marker (within a time span of 12 hours). The enzymatic activity in the thoracic BM section provides for calculating the age of the deceased person.