In order to understand action potential from an Oriental studies perspective, the change of membrane potential during the period in which action potential occurred was analyzed using Chou Tun I's “Explanation of the Diagram of the Supreme Ultimate.” The results are as follows. The change of the membrane potential, used by the neurons to generate electricity for information conduction, starts with the opening and closing of the ion channels. This is interpreted by Oriental studies through the following saying, “The movement of closing something once and then opening something once with the resulting change is called transformation.” The image of the moving action potential, or to be more precise, the change in the membrane potential follows the Yin & Yang and the Five Element Theory so that yin and yang are depolarization and repolarization, and the five elements are as follows: wood is phase I (the time from when resting membrane potential reaches the threshold), fire is phase II (rapid depolarized state), metal is phase III (action potential falling phase), and water is phase IV (hyperpolarized phase). Soil is not a specific phase but the harmony that is formed from all the phases inherent to action potential.