Since Li Shizhen of the Ming dynasty proposed the theory of “brain is the house of original spirit”， “Who is in charge of mental activities” has been debated for more than one hundred years ， and this issue remains to be unsolved. This paper discusses the conception of “natural endowment” and “belief systems”， provides a reference theory model for the relationship among heart， brain， and mental activities，and endows “t he theory of heart and brain are both in charge of menta1activities”with new connotation. The theory in this thesis not only helps to resolve disputes about “Who is in charge of mental activities”，but also conducts to develop new and effective technology of personality reconstruction and potential development.