Ethical issues are important because they concern with the order among people as well as values. These issues are especially important in societies with plurality nowadays. Among Confucians, Tseng-Tzu grasps the central ideas of Confucius’ ethical thought. Therefore, understanding Tseng-Tzu’s thought is helpful to get a clearer picture of Confucian ethical thought. This essay has five parts to concern with Tseng-Tzu’s ethical thought. The first chapter is a discussion of the studies of Tseng-Tzu’s thought. In the next chapter, I will show that Tseng-Tzu inherited the virtues benevolence (ren 仁), rites (li 禮) and filial piety(xiao 孝) from Confucius and how he practiced these virtues in his life. In the third chapter, I attempt to show how Tseng Tzu built his views of cultivation and filial piety through the view of body to construct his ethical thought. In the fourth chapter, I will discuss the issues about Tseng-Tzu’s ethical thoughts, including family relations, such as parents and children, husband and wife and elder brother and younger brother, and political and social relations, such as monarch-subject and friendships. Finally, I suggest we can find ways to solve family and social problems. Although the world is not the same as before, we can solve the family problem with Tseng-Tzu’s reconstruction of xiao, solve the conflicts among people with his view of cultivation, and solve the problems of hurting bodies with his view of body. Therefore, I suggest Tseng-Tzu’s thought can be applied to today.
Keywords：Tseng-Tzu, ethic, xiao, view of body, theory of cultivation