Aubenas was taken hostage with her driver in Baghdad more than seven weeks ago.
"My name is Florence Aubenas. I'm French. I'm a journalist with Liberation," she said on the undated tape released on Tuesday, speaking in English and looking distraught and exhausted.
"My health is very bad. I'm very bad psychologically also," she said, staring at the camera intently. Dressed in a grey sweatshirt and black trousers, she sat with her knees drawn up to her chest in front of a dark red background.
Her plight underscores the security crisis in Iraq, where a new post-election government yet to be formed faces bombings, shootings and kidnappings in anti-US attacks that show no signs of easing nearly two years after the US-led invasion of the country.
The videotape is the first of Aubenas, 43, to be broadcast since she and her Iraqi driver Husain Hanun al-Saadi - who does not appear in the tape - were seized in Baghdad on 5 January.
The French government also revealed on Tuesday that it had received another tape, and had shown it to Aubenas's family last week, but did not say what it depicted.
Francois Sergent, the foreign editor of Liberation, said: "It is both what we feared and what we hoped for.
"It is a sign that they are alive, of course, but we also feared this because the hostages are being held in conditions that make the pictures terrible to see."
Looking frail, Aubenas sounded desperate and appealed for help to a French parliamentarian.
"My name is Florence Aubenas. I'm French. I'm a journalist with Liberation. My health is very bad. I'm very bad psychologically also"
"I ask particularly for the help of the French deputy Didier Julia. Help me Mr Julia, help me. It's urgent," she said.
Julia, a member of the lower house of parliament from President Jacques Chirac's UMP party, went to Iraq last September on a freelance effort to try to secure the release of two other kidnapped French journalists.
The effort failed and the government denied it had approved his intervention.
When the journalists, Christian Chesnot and Georges Malbrunot, were finally released in December after four months in captivity, they criticised Julia's mission.
A senior member of France's ruling conservative party said his government told Julia on Tuesday not to undertake any personal initiative to help Aubenas.
However, Julia said he was willing to help - but only if the government lifts restrictions.
"I am in a situation where I am 'paralysed'. It depends on the government, whether it will give me a free hand or not," he said.
Didier Julia failed to rescue two
French journalists last year
He added he had been "stunned" when he "heard this call for help".
Aubenas is one of two female journalists being held in Iraq.
Italian Giuliana Sgrena, a reporter for Rome daily Il Manifesto, was abducted early last month in Baghdad. A tape of her pleading for her life was released nearly two weeks ago.
Iraqi Interior Minister Falah al-Naqib said on Tuesday he believed that Sgrena was alive. "I hope we will have good news soon, God willing," he said.