About 300,000 Russian troops, 1,000 aircraft and 36,000 military vehicles are taking part in the exercise, which is the biggest in the country since Zapad-81 at the height of the cold war.
Defense Minister Sergei Shoigu said Russia's military forces in the country's east were on high alert ahead of a five-day "snap inspection" of troops to pave the way for the massive exercised called Vostok-2018.
Vostok 2018 comes amid increasing tensions between Moscow and the West over Russia's involvement in the conflicts in Ukraine and Syria.
The main aim was to check the military's readiness to move troops large distances and test how closely infantry and naval forces cooperated.
The Russian defence ministry released video footage of military vehicles, planes, helicopters and ships getting into position for the initial stage of the drills.
Experts said in reality neither China or Russian Federation believe the two are close to a full-fledged military alliance, but the joint drills nonetheless reflected how much more cooperative the two countries' relationship has become, after decades of suspicion during the Soviet period.
Tanks roll during the military exercises in Chita, Eastern Siberia, during the Vostok 2018 exercises, September 11, 2018.
"It fits into a pattern we have seen over some time - a more assertive Russian Federation, significantly increasing its defense budget and its military presence", the alliance's spokesman Dylan White said late August.
Maintaining Russia's defence capabilities is "justified as rival powers are frequently quite aggressive and unfriendly", Kremlin spokesman Dmitry Peskov said in August in comments carried by state news agency, TASS.
Last month, the Kremlin's spokesman said Russia's "ability to defend itself in the current worldwide situation which is often aggressive and unfriendly to our country is justified, essential and without alternative".
Russian Federation on Tuesday launched its biggest war games since the fall of the Soviet Union - teaming up with China in a massive show of force that North Atlantic Treaty Organisation decried as a drill for "large-scale conflict".
China has sent about 3,200 troops, 900 combat vehicles and 30 aircraft to join the drills at Tsugol.
"The war games have laid a foundation for China and Russian Federation to enhance cooperation on global arena and will lift the combat proficiency of both sides", he said. "These are very important drills but they are part of routine annual work to develop the armed forces", he said.
The drills are being held in Russia's Eastern and Central military districts, which encompass more than half of the country's territory.