The invitation was open to New Zealand-based chief executives and chairman only, who would have to meet their own travel and accommodation costs.
One exporter who had received an invitation said Chinese distributors and customers would be impressed by getting an opportunity to meet Key.
"In China you just can't do that," the exporter said. "Getting into a room with the Chinese President - that's just never going to happen. The fact that there is such good access to the Prime Minister will definitely be appreciated."
It's understood that around 30 New Zealand companies have been invited to the meet-and-greet session.
New Zealand infant formula exporters are currently facing a raft of regulatory changes in China and there is uncertainty in the industry around the outcome of an audit of local manufacturing facilities by Chinese officials this month.
Key is also scheduled to meet Chinese President Xi Jinping and Premier Li Keqiang while in Beijing.
A statement released by the Prime Minister's office said the visit would focus on increasing agriculture, food safety and financial sector cooperation, as well as "building on the strong bilateral trade, economic and political relationship".
"My visit provides an opportunity to brief China's leaders on the outcomes of the Government inquiry into the whey protein concentrate contamination incident," Key said in the statement. "I will be able to report to China's political leadership, and assure Chinese consumers, that the inquiry delivered a strong endorsement of the New Zealand food safety system."
After visiting Hong Kong and Mainland China Key will travel to The Netherlands to attend the third Nuclear Security Summit in The Hague.
China overtook Australia to become New Zealand's largest trading partner last year and bilateral trade is expected to hit $20 billion by 2015.