This paper is to study the meanings and values of the problems of life and death in the modern society. The new science 'Thanatology' is in the process of becoming. We need to comprehend life and death newly through new, various interpretations for death in order to overcome the crisis of humanity in bioscience and medical science. In this situation we must examine the scientific method and research into the life and death first of all. Death means physical death in medical science. Physical death classifies clinical death and biological death. Clinical death is defined as a state without breath and heart pulse, without the activities of the brain. From the legal point of view, we define death as the standstill of life, exactly the whole standstill of breath and blood circulation, animal function for life as heart pulse. There are three decisions about the death of human being, namely cardiac death opinion, brain death opinion and cytological death opinion. Cardiac death opinion means that the heart as one of the most important organs is completely stopped. Brain death opinion defines death as the state of the complete loss of the functions of brian, specially of brain stem which controls all functions of the human being, as the state in which the recovery of the brain functions is impossible. According to the cytological death opinion it is necessary for each cell of the human body to have chemical, physical and physiological activities. But when these activities are destroyed to the state where the recovery of these activities is impossible, this state is defined as death. Therefore the complete stop of the organic activity of each cell is similar to stop of the heart. The death in the sense of stop of the heart is consequently called the death of the individual. Death in the sense of biology means the state where organism loses life irreversibly. The research into the life and death should be done in the point of meaning and value, in the context of the whole life. Consequently it is necessary for us to research culture, history, philosophy, literature, religion on the base of medical science, and then on the base of humanities. In this sense the problem of life and death is the best object of research for fusion study. Biological, medical research and that of their meanings through the fusion study will give us a new interpretation and point of view for the problem of life and death, for the cultural context of the death and the mutuality of life and death. These problems are the questions about the essence of the human being. Besides explaining for phenomenal and physical, functional dimension about life and death, we must search the meanings of life and death on the ground of fusion study synthetically. In this sense thanatology which is to study the meanings for life and death will be able to accomplish the goal of fusion study appropfe tely. Therefore we must connect biology, medical science, cerealum neutheogy with the humanities study, through the results of these explorations, the radical, original reflections we will be able to accomplish more inclusive research for the relation of brain and mind. The reflections on death change the attitude and standpoint which look at life, and lead to the meaningful life. These days many people believe that there is only scientific explanation for death, so we can not understand death itself and the dying more deeply and we all havlanarong tendency to think death itself unhappy or afraid. In this situation we want to give the right meanings for death to the people in pain of death bntific eays many arospection of humanities for death. In the end, we want to In w that the very purpose of thanatology of homo-humanitas is to think of death as a natural process of life.