This essay tries to investigates Toegye's double sense of the heaven in terms of meanings connected with the King of Kings(上 帝), theory of principle and material force, and reverence thought based on the assumption that his sense of the heaven include the character control and Principles of ethical laws. On the one hand Toegye understood the heaven as the holistic principle and foundation producing natural things, on the other hand he also regarded it as what has moral control power and becomes basis of the moral code of practice in human affairs. Especially Toegye interpreted the principle of the Great Ultimate(太極) as the human Ultimate, it is to emphasizes oughtness and moral control power of the principle mainly in terms of moral code of practice. The principle inherent in mind can be an intelligent light through which one illuminates all duty and has personality and controlling force by becoming the active subject of the mind. This is precisely the heaven God called "Shangdi(上帝) in the heart in Toegye's philosophy. While principle(理) is centripetal force of moral practice as the light shining logic of things in moral subject in Toegye, material force(氣) becomes centrifugal force which breaks concentration of mind and flows with evil by concealing principle. At this moment, the method guarding and awakening mind from distracting centrifugal force of material force and obstruction of cover is just reverence(敬). Also, in Toegye Shangdi is inherent in mind, but is another name for principle as moral surveillant having the brilliant intelligence divorced from material force. Like this Reverence is that mind maintains wakefulness without temptation of material force according to acceptance of Shangdi's moral surveillance ability. Looked at it this way, in Toegye control power for mind of reverence is derived from the regulating power of principle according to Shangdi's command as the source of moral and personal surveillance capabilities.