Dmitri Medvedev, the candidate favoured by Russian President Vladimir Putin to replace him, has launched a nationwide tour ahead of the elections.
Dmitri Medvedev is way ahead of his three rivals in opinion polls
Mr Medvedev attended an event marking the Battle of Stalingrad's anniversary, as campaigning officially began.
His rival candidates are Communist Party leader Gennady Zyuganov, the nationalist Vladimir Zhirinovsky and the little-known Andrei Bogdanov.
Mr Medvedev is seen as clear favourite ahead of the 2 March presidential poll.
He was shown on state television on Saturday laying a wreath at an "eternal flame" that burns in honour of those who fell at Stalingrad.
The six-month World War II battle, which ended 65 years ago, was a turning point in the Soviet Union's struggle against Nazi Germany.
Thousands of veterans reportedly turned up for the ceremony in the southern Russian city, which is now known as Volgograd, 900km (550 miles) south-east of Moscow.
Attending in his official capacity as first deputy prime minister, Mr Medvedev was quoted by Russian news agency Interfax as saying: "The exploits of Stalingrad are written in gold letters in the history of our fatherland.
"We must do all we can to ensure their memory lives on and to protect this monument."
President Putin has named Mr Medvedev, 42 - who also runs the state gas giant Gazprom - as his chosen successor. He is way ahead of the other three candidates in opinion polls.
His closest rival, Mr Zyuganov, has failed to mount a serious challenge since the mid-1990s.
Veteran nationalist Mr Zhirinovsky is unlikely to gain more than a tenth of the vote, while Mr Bogdanov's tiny Democratic Party is only polling around 1%, say correspondents.
If Mr Medvedev wins, as expected, Mr Putin is poised to become prime minister and interest will then focus on how much power Mr Putin retains, analysts say.