Kim headed back to Pyongyang on his private jet, called Chammae-1, which took off from the Beijing international airport at around 5 p.m. (local time), Yonhap news agency reported.
During his third visit to China in less than three months, Kim had a meeting with Xi to discuss Pyongyang-Beijing relations and the denuclearization issue.
His departure came hours after a visit to a farming science centre in Beijing, a possible sign that his regime was increasingly interested in agricultural reform, the report said.
Earlier in the day, two VIP sedans and other vehicles presumed to be carrying Kim and his delegation were seen leaving the Diaoyutai state guest house for foreign dignitaries. A motorcade was later spotted entering the research centre.
It is said to be the same facility that a group of North Korean officials led by Pak Thae-song, vice chairman of its Central Committee of the Workers’ Party of Korea, had toured during their trip to China in May.
Kim also appeared to have toured the Beijing Infrastructure Investment Co. Ltd, a move probably related to his push for partnerships in the infrastructure construction sector, including the envisioned Trans-China Railway (TCR).
The TCR programme is designed to link Seoul and Beijing by train through the North’s cities of Pyongyang and Shinuiju.
According to North Korean media, Pak and North Korean Prime Minister Pak Pong-ju, known for their expertise on science and the economy, were among the officials accompanying Kim.
Kim’s latest trip to China came a week after he held a historic summit meeting with US President Donald Trump in Singapore, in which he affirmed his commitment to denuclearization in return for security guarantees.
On the Kim-Xi summit, the North’s Korean Central News Agency earlier reported that the Chinese President expressed strong support for denuclearization efforts and promised to continue to play a “constructive role” in the process.