From the perspective of ethics, discuss the complete process of forming the five elements theory which developed from mutual promotion to the mutual restraint, and even then to the state of mutual promotion and restraint at the same time. Methods: By applying the metaphorical mapping theory, the way of mapping the code of ethics to the five elements in TCM was investigated from the aspects of family, humanity and political rights. Results: mapping the code of ethics to the five elements in TCM promoted the five elements theory. Conclusion:The powerful defender of the rationality of TCM theory is the moral value of the good in ethics. The constant pursuing of the good gives TCM vitality to develop up to now. Researching the five elements theory from the perspective of ethics can not only explore the humanistic connotations and the causes of formation of TCM theory, but also provide a new dimension to understand the five elements theory.