Russian President Vladimir Putin has arrived in Crimea, his first trip to the region since its annexation.
The triumphant trip to Crimea follows a massive show of military muscle in the annual Red Square parade marking victory over Nazi Germany in 1945.
The celebrations come at a time when the world's attention is focused on Ukraine where pro-Russian insurgents are preparing a referendum on secession.
Crimea, which hosts a major Russian Black Sea Fleet base, was annexed by Russia in March in a hastily called referendum held weeks after Russian troops took over Ukraine's Black Sea peninsula.
The presidential press service says that Mr Putin is to attend a massive navy parade in the port of Sevastopol.
Mr Putin made no reference to the situation in Ukraine when he opened the parade, focusing on the historic importance of the victory over Nazi Germany.
Victory Day is Russia's most important secular holiday and a key element of the national identity, reflecting the nation's enormous suffering and honouring millions of victims of the Second World War. .
About 11,000 troops proudly marched across Red Square to the tunes of marches and patriotic songs. Some 150 military vehicles and about 70 combat aircraft took part in the show.
This year's Victory Day comes as Russia is locked in the worst crisis with the West since the end of the Cold War.
The West and the Ukrainian government accuse Russia of fomenting the unrest in Ukraine's east, where insurgents have seized government buildings in a dozen of cities and fought with government troops.
They set a referendum on independence for Sunday, a vote similar to a plebiscite that paved the way for Moscow's annexation of Crimea in March.
Mr Putin's surprise call on Wednesday for delaying the referendum in eastern Ukraine appeared to reflect Russia's desire to distance itself from the separatists as it bargains with the West over a settlement to the Ukrainian crisis.
But insurgents in the Russian-speaking east defied Mr Putin's call and said they would go ahead with the referendum. While reflecting the anger against the central government shared by many in the east, the move also supported Moscow's denial of engineering the mutiny.
Mr Putin also said Russia had withdrawn its forces from the Ukrainian border, but Pentagon spokesman Steve Warren said there had been no evidence of a pullback.
The United States and the European Union have slapped travel bans and asset freezes on members of Mr Putin's entourage in response to Russia's annexation of Ukraine's Black Sea region of Crimea.
Despite the sanctions, Mr Putin is set to travel to France in early June for a ceremony marking the 70th anniversary of the D-Day invasion, his first encounter with Western leaders since the start of the Ukrainian crisis.