The origin of surname Ji, derived from an ancient surname in Zhou Dynasty, could be traced back to Yan Emperor in prehistoric period.
In Zhou Dynasty, royal court paid respect to the descendants of ancient imperial kinsmen and granted them with titles and territories. One branch of Yan Emperor's descendants established the state of Ji (today's Shouguang, Shandong province) when they were given this prefecture as a fief. From then on, imperial offspring of State Ji took Ji as their surname, and passed it down to generations.
By People's Daily Online