Abstract: The ZHOU's three brothers were important figures in Chinese society in the 20th century, especially LU Xun and ZHOU Zuoren, who were at the center of modern culture and intellectual history. There were indefinable relationships between the three brothers, especially LU Xun and ZHOU Zuoren. According to LU Xun's Diary, in terms of time, LU xun had a close contact with his first younger brother ZHOU Zuoren before July 1923; and since then he had frequent exchanges with ZHOU Jianren, his second younger brother. In terms of space, LU Xun mainly communicated with ZHOU Zuoren in Beijing, and with ZHOU Jianren in Shanghai. In terms of their contents of communication, LU Xun and ZHOU Zuoren were jointly engaged in such activities as teaching, writing, translation and running magazines, etc., focusing more on the cultural activities, namely the spiritual level, while the communication between LU Xun and ZHOU Jianren, focusing more on the material life.