Mr Putin (left) and Mr Xi last met in person in Beijing in February
The two will meet in Uzbekistan at a summit that will show an "alternative" to the Western world, the Kremlin said.
Mr Xi is making his first trip overseas since the beginning of the pandemic.
He is seeking a historic third term while Mr Putin's relations with the West are at rock bottom over Ukraine.
Mr Xi is beginning his three-day trip in Kazakhstan on Wednesday. He will then meet Mr Putin on Thursday at the Shanghai Cooperation Organisation (SCO) Summit in Samarkand, which will run from 15-16 September.
Mr 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.
He said the summit was taking place "against the background of large-scale political changes".
China and Russia have long sought to position the SCO, founded in 2001 with four ex-Soviet Central Asian nations, as an alternative to Western multilateral groups.
Mr Xi's visit comes amid a fresh set of lockdowns in China, where his zero Covid policy is still in place. While the rest of the world has opened up, learning to live with with the virus, Beijing continues to shut down entire cities and provinces every time there is a spurt in cases.
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.
China too 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.
China watchers say Mr Xi's decision to leave China after more than two years, despite significant domestic challenges - crippling lockdowns and a faltering economy - show his confidence in his leadership.
Analysts expect him to be re-elected for an unprecedented third term at the upcoming Chinese Communist Party Congress in October.
The SCO is a Eurasian political, economic and security organisation that was founded by China, Russia, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan in 2001. Iran is currently looking to join the group.
Members will discuss trade at the summit, with China being a major investor in the region through its Belt and Road projects.
Beijing has long looked to open up new rail routes for its trade to Europe, while Central Asian countries are eager for more connections to China.
Earlier this year, Kyrgyzstan announced it would begin construction in 2023 on a new line connecting it to China and Uzbekistan.
-- Courtesy of BBC News