Xi welcomed Putin with a ceremony at the Great Hall of the People only days after meeting US President Donald Trump.
The quick succession of Trump's and Putin's visits highlighted Beijing's growing role as an international superpower, experts say.
Putin greeted Xi warmly as they met for bilateral talks at the Great Hall of the People.
"My dear friend," Putin said on Wednesday.
"We are truly delighted to see you. We keep in constant touch, both personally and through our aides in the government."
Xi also stressed the "political mutual trust and strategic co-operation" between the countries, according to Chinese state media.
The two leaders have praised each other profusely in the past, with Xi at one point describing Putin as his "best and most intimate friend".
Xi and Putin were set to focus on energy and security as well as their overall ties.
The two sides agreed to extend a friendship treaty first signed in 2001, Chinese state media reported.
China became Russia's top trading partner after Moscow's full-scale invasion of Ukraine in 2022.
Beijing has said it is neutral in the conflict while maintaining trade ties with the Kremlin despite economic and financial sanctions by the US and Europe.
China is the top customer for Russian oil and gas supplies, and Moscow expects the war in Iran to increase the demand.
In his meeting with Xi, Putin stressed their countries' economic ties.
"The driving force behind economic co-operation is Russian-Chinese collaboration in the energy sector," Putin said.
"Amid the crisis in the Middle East, Russia continues to maintain its role as a reliable supplier of resources, while China remains a responsible consumer of these resources."
Xi stressed the need of "complete cessation of hostilities" in the Middle East, according to Chinese state media.
"An early end to the conflict will help reduce disruptions to energy supply stability, the smooth flow of industrial and supply chains, and international trade order," Xi said.
A Russian presidential aide said earlier that Russia's oil exports to China grew by 35 per cent in the first quarter of 2026 and Russia was one of the biggest exporters of natural gas to China.
Putin also stressed China and Russia's co-operation in foreign policy as "one of the key stabilising factors on the international stage".
In February 2022, just weeks before Russia's invasion of Ukraine, China and Russia announced a "no limits" partnership during a trip by Putin to Beijing.
Beijing says it is neutral in the conflict, though in practice it supports Moscow through frequent state visits, growing trade and joint military drills.
China has also ignored demands from the West to stop providing high-tech components for Russia's weapons industries.
The two leaders are scheduled to sign co-operation agreements during Putin's two-day visit.
But regardless of specific deals, the primary purpose of the visit is to reaffirm the countries' ties as well as project Beijing's image as an influential superpower, experts say.
