Abstract: According to psychoanalytic practice, Freud put forward a dynamic model of personality. He divided personality into three systems, including id, ego and superego. Undoubtedly, his theory contains the dialectical thought of the contradictory struggle between desire and morality, which is reflected in the ‘war’ between the id and superego. However, he excessively emphasized on biological instinct, and paid too much attention to repression and conflict. As a consequence, the complementary characteristic of contradictions was neglected. In fact, the mental structure of human beings situates in the intermediate state of "nature-morality", and it can be understood by means of "Yin and Yang" thought in Chinese philosophy, complementing with Freud's theoretical views. Some researchers have proposed a mental model of Tai Ji diagram on the basis of Freud’s early viewpoints. However, this model seems to be not enough. This paper aims to explain the development and existential states of ego according to Freud’s personality theory and Yin-and-Yang-fish diagram. Firstly, from the perspective of the Tai Ji diagram, the id and superego represent Yin and Yang that are derived from two parts of life, and the ego is the Tai Ji diagram that is composed of Yin and Yang. However, an individual gradually realizes that he is consist of aesthetic ego (i.e., Yin fish) and the ethical ego (i.e., Yang fish) during the process of pursuing or establishing existence and security. The Yin fish represents the unique and uncertain, passionate and impulsive id, while the Yang fish represents the strict and ethical, safe and transparent superego. Secondly, ego includes three existential states: (1) "aesthetic ego", which mainly consists of "Yin fish"; (2)"ethical ego", which mainly consists of "Yang fish"; and (3) "perfect ego", which means Yin is in harmony with Yang. Thirdly, the development of yin-yang follows a double-helix structure which consists of fish tail, fish head and fish eyes. Concretely speaking, the developmental process of "Yin-fish-ego" starts from natural (sensory) desire to reflective (rational) aesthetics, and then to the ethicalization of aesthetics; the developmental process of "Yang-fish- ego" begins from natural emotion to rational ethics, and then to the aestheticization of ethics. However, Yin and Yang usually gain different advantages at different stages of life. Finally, individual life originated from the unconscious is influenced by experiences and culture. The ego transforms from passive acceptance to initiative establishment, from unconsciously persuing meaning to consciously realizing value, and finally achieves transcendental and satisfactory state. During this process, the adolescence is dominated by aesthetic ego, the adulthood is dominated by ethics ego, and the task in senility period is to pursue "perfect ego" in order for harmony and unity. Future research can start from the following aspects. Foremost, the personality structure of Yin-and-Yang-fish diagram can be used to deal with the problems of personal fragmentation, depression and mania, even to explore the Yin and Yang model of interpersonal interactions. Furthermore, the future research can analyze the individual mind by combining the self-cultivation thoughts of Confucian social person and Taoist natural persons, in order to develop an almost perfect self of individual. Finally, the features of Yin-Yang-fish diagiam is integrative, dialectical, developmental and dynamic, including the philosophy of harmony of man with nature. This means it can be helpful for constructing and analyzing the structure and development of mind. On the other hand, there is no such thing as supremacy between Yin and Yang. They are equal and develop with the consciousness, or even bypassing the consciousness. That is different from the biological sexual instinct determination theory of Freud. In Freud’s opinion, the id has exceeded the individual it belongs to and looks like “the God” that thinking aims to wipe out the concept of individual and make people a group or a species. Yin Yang fish character is intended to provide different status of life or existence, not a standard to become a person. People has the freedom to choose the status they are in. The psychological mission of this concept is to explain and describe the contradiction and balance in every mental scenario for precaution. “That is why people living in a nest can tell the wind and the people in a cave can tell the rain. Taking what you worry about and Making what get you safe last. ”Yin Yang fish character emphasis the precaution to the imbalance instead of control, not defining people to a certain pattern. Last but not least, the Western scholars have been interested about the Yin Yang theory of China long ago. For example, the philosopher Leibniz found the meaning of Yin Yang in mathematical “binary algorithm”，the enthusiasm for Taoism classics of Jung and the use of Yin Yang perspective to explore management issues about cooperate competitions and cooperation by the modern Western scholars. In addition, as our society is on the period of transformation and shock brought by post-modern self-concept, the spiritual structure of the people is facing great changes and severe challenges and more and more people are getting out of balance. The same situation applies to Wei and Jin Dynasty , World War II and globalization nowadays. So it is very important for us to have the construction of our spiritual structure by reviewing the influence and value of traditional Chinese thinking to the modern society.

Key words: Yin-Yang theory, Psychoanalysis, Ego, Personality structure

摘要： 随着临床实践的深入，弗洛伊德在后期对人格结构进行了调整，提出了精神的动力结构，但他在其精神结构中过分强调个体的生物性本能，忽略了矛盾既相互对立又相成相济。事实上，处于“自然-道德”中间状态的人的精神结构，可以用中国哲学中的“阴阳”来理解，即在结构上注重阴阳的对立与平等，在发展上强调阴阳在不同时期的发展和变化。阴阳太极图与弗洛伊德后期的人格理论的中西互补，能够加深对徘徊在自然-道德之间的人的认识，从而为重新审视中国传统思想之于现代和当代精神结构的建设有着重要的启示和价值。

关键词: 阴阳, 精神分析 , 自我, 人格结构