Xi, whose country is locked in a tariff war with the United States, is expected to sign numerous agreements to deepen the already tight "no limits" strategic partnership with Moscow, which has consistently seen China crowned Russia's biggest trading partner.
China buys more Russian oil and gas than any other country and has thrown Moscow an economic lifeline that has helped it navigate Western sanctions imposed over its war in Ukraine.
Despite recent efforts under US President Donald Trump to reset US-Russia ties, Putin is expected to present a united front with Xi against Washington, whose dominance and "exceptionalism" both countries have questioned, arguing for a more multipolar world instead.
"The upcoming visit of Chinese President Xi Jinping to Russia is one of the central events in Russian-Chinese relations this year," Russian Foreign Ministry spokeswoman Maria Zakharova told reporters on the eve of the visit.
"The upcoming Russian-Chinese summit will send an important signal to the international community about the common approaches of Russia and China in defending the post-war world order," she added.
Trump's special envoy Keith Kellogg said in February that Washington would try to disrupt Russia's close ties with countries like China. Days later, Xi and Putin reaffirmed their countries' "no limits partnership".
Xi, who has told Putin that the two have a chance to drive "changes the world has not seen in a century", is due to hold talks with Putin on Thursday. He will join other world leaders on Moscow's Red Square on Friday to watch a military parade to mark the 80th anniversary of the victory of the Soviet Union and its allies over Nazi Germany.
The event, which will also feature Chinese troops, comes at a time when Trump is trying to push Moscow and Kyiv to find a way to end the war in Ukraine with both sides so far blaming each other for a lack of progress.
But Xi, who has called for talks to end the conflict and has accused the US of stoking the war with weapons supplies to Kyiv, will be attending anyway, according to Beijing and the Kremlin.
Moscow and Beijing sealed their "no limits" strategic partnership days before Putin, who in recent months has described China as an ally, sent tens of thousands of troops into Ukraine in February 2022.
Putin and Xi will discuss the "most sensitive" issues, including energy co-operation and the proposed but yet to be built Power of Siberia 2 gas pipeline to China, Ushakov, a top Kremlin aide, said.
Putin is expected to visit China at the end of August or the start of September, the aide added.
