Zengzi or Master Zeng (Chinese: 曾子; pinyin: Zēngzǐ; Wade–Giles: Tseng Tzu, 505–435 BC), born Zeng Shen or Zeng Can (曾參), courtesy name Ziyu (子輿), was an influential Chinese philosopher and disciple of Confucius. He later taught Zisi (Kong Ji), the grandson of Confucius, who was in turn the teacher of Mencius, thus beginning a line of transmitters of orthodox Confucian traditions. He is revered as one of the Four Sages of Confucianism.

Zeng Shen was 46 years younger than Confucius. He was a native of South Wu City in the State of Lu, and was the son of Zeng Dian, one of the earliest disciples of Confucius.

When he was sixteen, he was sent by his father to study under Confucius. Confucians later considered him to be his second most senior student, after Yan Hui. Duanmu Ci said of him, "There is no subject which he has not studied. His appearance is respectful. His virtue is solid. His words command credence. Before great men he draws himself up in the pride of self-respect. His eyebrows are those of longevity." He was noted for his filial piety, and after the death of his parents he could not read the rites of mourning without being led to think of them and being moved to tears. He was a voluminous writer. He composed ten books, compiled in the Rites of the Elder Dai (大戴禮). He was said to have composed and/or edited the Classic of Filial Piety under the direction of Confucius. He was also associated with transmission of the Great Learning. He was first associated with the sacrifices to Confucius in 668 AD, but in 1267 he was advanced to be one of Confucius' Four Assessors. His title, "Exhibitor of the Fundamental Principles of the Sage", dates from the reign of the Jiajing Emperor, when he was associated with Yan Hui.

Zengzi established his own school, and taught Zisi (Kong Ji), the grandson of Confucius, who was in turn the teacher of Mencius, thus beginning a line of transmitters of orthodox Confucian traditions. Along with Yan Hui, Zisi, and Mencius, Zengzi is considered to be one of the Four Sages of Confucianism.

Filial piety

Zeng Shen was known for his filial piety. After the deaths of his parents, he was unable to read the rites of mourning without bursting into tears.