Many pro-Kremlin supporters are expected to wear St George's stripes - a symbol of Russian military valour
In Kiev on Friday, people lit candles and laid flowers to remember Ukrainian activists shot dead last February
Light beams pierced the night sky in Kiev in memory of the fallen "Heavenly Hundred"
Russian government supporters are to rally in the capital Moscow to mark the first anniversary of what they view as a "coup" in neighbouring Ukraine.
Thousands of people are expected for the march which has been actively promoted in Russia's state media under the slogan "Let's not forgive!"
Ukraine's protests ousted pro-Russian President Viktor Yanukovych in 2014.
Russia has since annexed Ukraine's Crimea peninsula and is accused of backing rebels in eastern Ukraine.
Ukraine, Western leaders and Nato say there is clear evidence that Russia is helping the separatists in the Donetsk and Luhansk regions with heavy weapons and soldiers.
Moscow denies this, insisting that any Russians serving with the rebels are "volunteers".
More than 5,400 people have died since the fighting erupted last April.
'Come, if you like your country!'
Russians are expected to come to Moscow from across the country for the "anti-Maidan" march - a reference to Ukraine's pro-EU protests that started on Kiev's central Independence Square, widely known as the Maidan.
In Kiev on Friday, people lit candles and laid flowers to remember Ukrainian activists shot dead last FebruaryLight beams pierced the night sky in Kiev in memory of the fallen "Heavenly Hundred"
Ahead of the Moscow rally, Russian state-run media urged all those who considered themselves "patriots" and were against "revolutions" to attend.
"Come, if you like your country!" Rossiya 24 TV channel said in its broadcasts.
The demonstration comes a day after Ukrainian President Petro Poroshenko accused Russia of direct involvement in the sniper fire that killed dozens of protesters in Kiev on 18-20 February last year.
Speaking at a commemorative gathering in Kiev, he said President Putin's aide Vladislav Surkov had organised "groups of foreign snipers". The president cited information he had received from Ukraine's security services.
The Russian foreign ministry hit back at the claim, calling it "nonsense".
The anti-Yanukovych revolt was triggered by a sudden U-turn that ditched a wide-ranging pact with the EU in favour of closer ties with Russia.
Rebel advance
Mr Poroshenko was speaking just two days after his army retreated from the key town of Debaltseve, now in rebel hands.
The rebels took the strategic transport hub, despite a ceasefire deal signed on 12 February.