Jingzi 景子 "Master Jing" was a Confucian treatise compiled by a certain Master Jing 景氏, who lived during the late Spring and Autumn period 春秋 (770-5th cent.) and was, according to Deng Mingshi's 鄧名世 (c. 1150) study Gujin xingming shu bianzheng 古今姓氏書辨證, a descendant of Duke Jing of Qi 齊景公 (r. 547-490). Other family members were counsellors in the state of Chu 楚, but it is not sure whether these Jing were related to those of Qi 齊.
The imperial bibliography Yiwen zhi 藝文志 in the official dynastic history Hanshu 漢書 says that the Jingzi was 3-chapters long. The Qing-period 清 (1644-1911) scholar Ma Guohan 馬國翰 (1794-1857) was able to find two fragments of the Jingzi in various books according to which Jingzi was a disciple of Mizi 宓子.
These fragments are to be found in Ma's series Yuhan shanfang jiyi shu 玉函山房輯佚書.