President Vladimir Putin is expected to attend the games after hosting an economic forum in Russia's far eastern city Vladivostok where his Chinese counterpart Xi Jinping is one of the prominent guests.
The week-long war games dubbed "Vostok-2018"(East-2018) "have kicked off" in far eastern Russia, the defence ministry said.
Taking part in the drills are around 300,000 soldiers, 36,000 military vehicles, 80 ships and 1,000 aircraft, helicopters and drones.
Some 3,500 Chinese troops will take part in the exercise.
The defence ministry released video footage of military vehicles, planes, helicopters and ships getting into position for the initial stage of the drills.
Putin praised Russia's increasingly close ties with China as he met Xi at the economic forum in Vladivostok on Tuesday.