No one was injured in the attack, .
The Paris prosecutor's office said counter-terrorism investigators are probing Friday morning's incident at the Chatelet station in the centre of the capital, based on preliminary examination of the attacker's background. The individual was not known to the police, the source added.
The person reportedly attacked the soldier with a knife.
The soldier was a part of the country's Sentinelle group, a military operation set up to protect Paris in the aftermath of terror attacks that have left hundreds dead in recent years.
The unidentified man is said to have rushed at a patrol of soldiers wearing combat uniforms and brandishing assault rifles.
"We do not know the intentions of the attacker, who was arrested", she told Europe 1 radio.
Recently, authorities said last month that six soldiers in Levallois, outside Paris, were hurt when a driver deliberately rammed into them.
Two women were injured on Friday by an attacker wielding a hammer and shouting Allahu Akbar in the eastern French town of Chalon-sur-Saone in Burgundy, local officials said. The suspect was arrested hours after the incident on a motorway in northern France.
France declared a state of emergency following attacks in Paris in November 2015, in which more than 130 people were killed.
The operation has been widely criticized, some consider it ineffective, or even a target of Islamist attacks, but reassuring for the population according to others.
He took the attacker under control following the attack.