Abstract: As the mainstream of modern science, natural history has developed from Foucauldian epistemological discourse to the important discourse of “scientific discourse community,” which has become the basis of legitimacy for a new culture and new thought that promoted the New Culture Movement. As the scientific discourse of the three Zhou brothers, natural history influenced Lu Xun’s (Zhou Shuren) “saving the nation through science” and “biological truth”, Zhou Zuoren’s “biological reference” and “naturalization of ethics”, as well as Zhou Jianren's “national evolution” and related ideas of new culture. Zhou Brothers' scientific discourse of natural history witnessed the unremitting exploration of Chinese intellectuals to join in the “scientific discourse community” in order to establish new culture and new ideas to enlighten the people and save the nation. It not only revealed the deep relationship between “Mr. Democracy” and “Mr. Science” in the New Cultural Movement, but also represented an important development in the history of modern Chinese thought, literature, and science.

Key words: Three Zhou Brothers, natural history, scientific discourse community, the New Culture Movement, biological truth