Abstract: The Harvard standard of brain death has been used as a routine standard of diagnosing death. Through tracing and analyzing the historical context and dynamics of defining brain death, the selection of the members of Harvard Ad Hoc Committee Brain Death, including their specific roles and underlying interest conflicts involved in organ transplantation, it is found that, as a product of medicalization and de-medicalization, the Harvard standard of brain and death represents the tension between medical humanities, medical professional and the public, as well as scientific medicine, social and culture forces.