The 34-year-old helicopter navigator faces up to 25 years in prison for her alleged involvement in the killing of two Russian journalists in war-torn eastern Ukraine last year.
Savchenko, who is seen by her compatriots as a symbol of resistance against what most Ukrainians consider an insurgency fuelled by President Vladimir Putin's government, has denied any involvement.
After more than a year in detention, Savchenko was in the dock in the small southern Russian town of Donetsk on the border with eastern Ukraine.
There was a heavy police presence for the trial, which started with a closed preliminary hearing.
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Embassy staff from several countries including Britain, the United States as well as the European Union were in Donetsk to observe the trial.
"She is okay," defence lawyer Mark Feigin said on Twitter after seeing Savchenko.
Her legal team -- including Feigin who said he took a flak jacket to Donetsk -- asked that the trial be moved to Moscow and away from a town near a conflict zone.
Donetsk has no jail and Savchenko has to be transported to hearings from Novocherkassk, a city nearly two hours away by car.
Few doubt that Savchenko's fate will be decided in the Kremlin, and Western leaders as well as Ukrainian President Petro Poroshenko of Ukraine have called on Putin to let her go.
Two journalists from Russian public broadcaster VGTRK, Igor Kornelyuk and Anton Voloshin, died in shelling on June 17, 2014, in Ukraine's Lugansk region.
The prosecution also accuses her of illegally crossing the border into Russia where she was detained.
Savchenko has denied the charges and refused food for more than 80 days to protest at her detention. She broke off her hunger strike in March because of severe health problems.