More than 25 warships and around 30 planes took part in the drills, as Russian Federation increased its military presence in Syria where it intervened to help the Bashar al-Assad regime in 2015.
President Vladimir Putin is expected to attend the war games after hosting an economic forum in Vladivostok where Chinese leader Xi Jinping is one of the guests.
Taking part in the drills are around 300,000 Russian soldiers, 36,000 military vehicles, 80 ships and 1,000 aircraft, helicopters and drones, as well as 3,500 Chinese troops. According to reports, Chinese soldiers are also taking part in the war exercise for the first time.
The Chinese media described the country's involvement as its largest-ever dispatch of forces overseas for war games.
Given the closeness to Alaska, some analysts believe Mr Putin is also seeking to send a message to the United States.
Russian Federation has substantially increased the size and frequency of its military exercises in recent years, particularly following its invasion of Crimea in 2014.
The ministry of defence said that nearly a third of its active military personnel was taking part in the week-long exercises in Siberia and the Russian far east, although independent analysts suggested that the numbers may have been overstated.
While both Russian Federation and China have said the manoeuvres are not directed against other countries they do coincide with Nato's Rapid Trident 2018 military exercise in Ukraine, which started on September 3 and ends on Saturday.
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".
"The focus of the drill has expanded from anti-terrorism to allied defense and counterattack", a China defense ministry statement said.
Russia's biggest-ever war games Vostok-2018 "have kicked off" in far eastern Russian Federation.
"This is a milestone for Sino-Russian military ties", Alexander Gabuev, a senior fellow at the Carnegie Moscow Center, wrote on Twitter.
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.
Russian Federation on Tuesday launched its largest military exercise at the Tsugol training range in Russia's Trans-Baikal region in eastern Siberia.
The country´s war games in Eastern Europe previous year, Zapad-2017, saw 12,700 troops take part according to Moscow.
For Russia, the increasingly robust alliance with China is particularly important amid the growing tensions with the US and its allies and a looming threat of more biting USA sanctions.
"Imagine 36,000 military vehicles moving all at the same time; tanks, armored personnel carriers, infantry fighting vehicles - and all of these in conditions as close to a combat situation as possible", Sergey Shoigu, Russia's defense minister, said this month.
He added: "Russia also thinks that the global reactions to its appalling behaviour over recent years - including the seizure of Crimea, aggression against Ukraine, causing and abetting untold suffering in Syria, the attempted murder of the Skripals and more - are just more indications of this "aggressive and unfriendly" attitude by the rest of the world".
On September 10, Peskov called Vostok-2018 part of "a regular, routine training process aimed at improving skills and coordination in our armed forces".