The PM will also meet Finance Minister Pierre Moscovici while in France - and he has a sales job to do: trying to persuade the EU to start free trade talks with New Zealand.
Mr Key said New Zealand was one of only five trading nations that did not have a free trade agreement or was not in talks with the EU towardsone.
He raised the same issue in Britain, and said France was also very influential and could be a powerful ally for New Zealand's case with the wider European Union.
Although trade with Asia was rocketing, he said New Zealand had learned the importance of diversification from the 1970s, when Britain entered the European Common Market.
"It had a dramatic impact on our economy back then. That was really because all our eggs were in the British basket. Now we just want to make sure we don't end up with all those eggs in the Chinese basket."
Mr Key said the German elections would also be discussed, and France's views on the future of the eurozone.