The two leaders are set to hold a cloak-and-dagger summit in the former Soviet state of Uzbekistan. The meeting has triggered fears of a growing alliance between Russia and China.
Mr Xi is making his first trip overseas since the start of the Covid pandemic.
He is seeking a historic third term while the Russian despot’s relations with the West are at rock bottom over Ukraine.
The Chinese President is beginning his three-day trip in Kazakhstan, where he landed in the capital Nursultan for the first leg of his trip on Wednesday.
He will then meet Putin on Thursday at the Shanghai Cooperation Organisation (SCO) Summit in Samarkand.
Putin will also meet other leaders including those of India, Pakistan, Turkey and Iran – but his meeting with China’s leader “is of particular importance”, said Kremlin foreign policy spokesman Yuri Ushakov.
“The SCO offers a real alternative to Western-centric organisations,” he said. “All members of the SCO stand for a just world order.”
Mr Xi last left China in January 2020 to visit Myanmar – just days before the first lockdown came into effect in Wuhan.
He has remained in China since then, leaving the mainland only once in July this year to visit Hong Kong.
Mr Putin is also making a rare foray abroad. His meeting with Turkish and Iranian leaders in Tehran in July was only his second foreign trip since Russian troops invaded Ukraine.
This is the two leaders’ second meeting this year – they last met at Winter Olympics in Beijing in February.
Following the February meeting, the two leaders issued a joint statement saying the friendship between their countries had “no limits”.
Russia invaded Ukraine days later – an action China has neither condemned nor voiced support for. Beijing, in fact, has said both sides are to blame.
China is not part of the international sanctions against Russia and trade between the two countries has continued to grow. Indian and Chinese imports of Russian oil have soared since the Ukraine invasion.
Beijing has seen its relations with the West and especially the US sour in recent months following tensions over self-ruled Taiwan. China claims the island as part of its territory.
Last month, Beijing staged a five-day military blockade around the island in response to US House Speaker Nancy Pelosi’s visit.
Analysts expect Mr Xi to be re-elected for an unprecedented third term at the upcoming Chinese Communist Party Congress in October.