Chinese Buddhist monk who systematized the teachings of the San-lun (“Three Treatises,” or Middle Doctrine) school of Māhāyana Buddhism in China and who is sometimes regarded as its founder.

Chi-tsang was the son of a Parthian father and a Chinese mother, but his education and upbringing were wholly Chinese. In an age characterized by social unrest and military struggle, he produced an astonishing volume of literary works, of which the best-known are his commentaries on the basic texts of the San-lun school. Because of his great reputation as a teacher and writer, Chi-tsang was invited by Emperor Sui Yang Ti to the capital, Ch'ang-an, where he lectured before huge throngs of monks and laymen.

The San-lun school's basic doctrine is that, while the things of the material world may possess a temporary reality or existence, on the level of absolute truth there is “no production or extinction, no permanence or annihilation, no unity or diversity, no coming or departure.” Although the school itself did not survive past the 9th century AD, many Chinese Buddhists continue to study Chi-tsang's teachings. Chi-tsang's ideas also influenced the Neo-Confucian philosophy of the Sung dynasty (960–1126).