Jǐ is the pinyin romanization of the present-day Mandarin pronunciation of the Chinese name written 濟 in traditional characters and 济 in the simplified form used in mainland China.

[2] Ancient Chinese accounts also wrote the name with the character 泲,[3][4] and Lin Chuanjia considered this to be identical with the Yuan River that gave Yuanqu County its name.

[11] Under the Han, the Ji River's central course passed through the Great Wild Marsh (t 大野澤, s 大野泽, Dàyězé) and its mouth was in Qiansheng Commandery (千乘郡, Qiānchéng Jùn).

[3] The area around the Ji River was among the most densely populated in China during the Neolithic Age,[12] when its plains were a center for the Longshan[13] and Yueshi cultures.

[17] In fact, the Heshui Canal (t 荷水運河, s 荷水运河, Héshuǐ Yùnhé) connecting the Ji to the Si was completed by soldiers under the command of King Fuchai of Wu in 483 and 482 BC in order to improve their supply lines while at war with the northern states of Qi and Jin.