Ji Bu hailed from Pengcheng 彭城 (modern Xuzhou 徐州, Jiangsu) and was known as a freelance-knight supporting the poor and fighting the powerful. Xiang Yu hired him when he passed Pengcheng and made him a general. During Xiang Yu's fight against Liu Bang 劉邦, Ji Bu proved to be an excellent strategist who often challenged Liu Bang. After Liu Bang's victory and proclamation as emperor of the Han dynasty, Ji Bu escaped to Puyang 濮陽 (modern Puyang, Henan) because Liu Bang offered a prize on his head.
Ji Bu's protector Master Zhou 周氏 sold him under a false name to Master Zhu 朱氏, who had connections with Xiahou Ying 夏侯嬰, a trusted minister of the emperor. Upon Xiahou Ying's intercession Liu Bang pardoned Ji Bu and even made him gentleman of the interior (langzhong 郎中).
During the reign of Emperor Hui 漢惠帝 (r. 195-188), Ji Bu was promoted to the post of Leader of the Court Gentlemen (zhonglangjiang 中郎將).
During that time, the steppe federation of the Xiongnu 匈奴 regularly raided northern Chinese territories. While Fan Kuai 樊噲 advocated dispatching a punitive expedition, Ji Bu was well aware that the imperial armies were too weak and the economical situation of the empire not yet stable enough.
During the reign of Emperor Wen 漢文帝 (r. 180-157 BCE), he was made governor (taishou 太守) of the commandery of Hedong 河東. The emperor even planned to make him (yushi dafu, but give up this intention when he heard of Ji Bu's inclination to wine.
Ji Bu died, highly estimated, in office.