There are 350 French nationals or residents in the region at the moment, Cazeneuve said, adding that 60 of them are women.
About 180 have left Syria and 170 are on their way there, while 230 have said they are planning to go, according to the minister.
A recent parliamentary report put the number of jihadis at 950, having registered 10 fewer people intending to go.
At least 70 people have been prevented or dissuaded from going thanks to a government hotline for parents and relatives of would-be jihadis that has received 350 notifications concerning 80 minors and 150 women, Cazeneuve said.
Some of those who have returned to France are ready to go back and fight again, Cazeneuve said, while others have been repelled by the violence that they have witnessed or participated in.
Cazeneuve’s announcement came as US Secretary of State John Kerry arrived in Paris for an international conference on fighting the Islamic State (IS) armed group, which now controls about 40 per cent of Iraq and a quarter of Syria.
Detailed decisions of the conference, mostly attended by foreign affairs minister and jointly chaired by French President François Hollande and Iraq’s Fuad Masum, may not be made public.
"We're not going to say who is going to carry out air strikes or when they might happen," a French diplomatic source told the AFP news agency.
After hearing that IS’s murder of aid worker David Haines, British Prime Minister David Cameron called a meeting of the Cobra emergency committee.
The British parliament voted against taking part in military action in Syria last year and Foreign Secretary Philip Hammond previously said the UK would not take part in air strikes there, although Cameron has refused to rule out any course of action.
Foreign Affairs Minister Laurent Fabius on Wednesday said France could take part in air strikes “if necessary”, although that would be more likely to be in Iraq, if the government asks for them, than in Syria, since Hollande has ruled out working with President Bashar al-Assad.
Australian Prime Minister Tony Abbott on Sunday committed 600 troops to the effort.