The Chinese media touted the Chinese involvement in the maneuvers as the country's largest-ever dispatch of forces overseas for war games.
In addition to mobilizing 300,000 Russian troops, the exercise includes 1,000 aircraft and 36,000 military vehicles, South China Morning Post reported, which is the biggest show of force since Zapad-81 drills at the height of the Cold War.
China is sending about 3,200 troops, 900 combat vehicles and 30 aircraft to join the drills at a Siberian firing range, a significant deployment that reflects its shift toward a full-fledged military alliance with Russian Federation.
The week-long exercise, known as Vostok-2018 (East-2018) "have kicked off" in far eastern Russian Federation, the defence ministry said on Tuesday.
China's participation in the exercises, known as the Vostok drills, exemplifies an overall expansion of collaboration with Russian Federation as an ally, the Kremlin has said. Also at one stage the exercises will be joined by soldiers from Mongolia and China.
But Defense Minister Sergei Shoigu said these exercises are even larger.
Vostok 2018 comes amid increasing tensions between Moscow and the West over Russia's involvement in the conflicts in Ukraine and Syria.
The weeklong manoeuvres come at a time of heightened NATO-Russia tensions.
- Up to 80 naval vessels and support ships from two Russian fleets will take part in the war drill, reports said.
In recent months the United States has imposed more sanctions over alleged Russian interference in the presidential elections and the poisoning of ex-double agent Sergei Skripal and his daughter in Britain.
Multiple Russian divisions, including the Pacific and northern fleets, are participating in the Vostok 2018 war games from September 11-17. The event, called Vostok or East 18, began as President Putin met President Xi of China.
"This is a milestone for Sino-Russian military ties", Alexander Gabuev, a senior fellow at the Carnegie Moscow Center, wrote on Twitter.
Therefore, I think that there is synchronized coordination between the Belarusian and Russian armed forces.
At the start of the military exercise on Tuesday, Putin said that Russia-China "friendship is getting stronger all the time". Russia's new military doctrine adopted the same year defines North Atlantic Treaty Organisation enlargement as a major threat to the country's security.
The Kremlin spokesman warned at the end of August: "Russia's defense capability in the current global situation, which is often quite aggressive and unfriendly to our country, is absolutely and unquestionably justified".