Abstract: In the ethical thoughts of Confucian philosophers in Song and Ming Dynasty,the “fall child” in Mencius was often cited as evidence for the human good nature.However,the meaning of this classic evidence is essentially more than an example.It reflects Confucian special emphasis on the natural emotion as the base for its whole ethics,which characterizes Confucian ethical thoughts and differs it from the rationalism in Western mainstream ethics.The character of Confucian ethics is helpful to the understanding of Chinese tradition and is also relevant to ethical construction in China today.

Key words: Confucianism, Ethics, Natural Emotion, Morality