Mr Patrapee said old clients who understood the situation in Thailand were not concerned about martial law but new clients could be worried by it.
Sumet Sudasna, president of the Thailand Incentive and Convention Association, said martial law had reduced political tensions.
"I think many foreigners have a better understanding of the political situation in Thailand. When I asked my clients in Belgium about their concerns over martial law, they told me that they are not worried about it," he said.
The Thailand Convention and Exhibition Bureau reported that the country welcomed 919,164 Mice tourists and generated 80.1 billion baht revenue in fiscal 2014.
In fiscal 2015, it targets 1.04 million Mice visitors with revenue of 107 billion baht