The academic circles have different opinions on the specific connotation of Plato’s temperance, and they often ignore the thought recognized by Plato in Charmides because it is an early work. On the whole, tem? perance in Plato’s philosophy is a quality that enables individuals to properly regulate their desires with rationali? ty on the basis of cognition, and makes individual rationality voluntarily submit to the ruler’s rationality, which ultimately leads to the harmony within the individual soul and the city-state. Plato’s temperance has internally natural and harmonious self-restraint, as a code of conduct, and it controls people’s desire and guides people’s behavior, and it is the prerequisite for people to acquire other virtues and live a happy life. It is not only the basic virtue that everyone should have in Plato’s city-state ethics system, but also an important virtue that is urgently needed to help people restrain desire, resist temptation and follow moral rules.