Sinovac will arrive on a Thai Airways flight at 8am on Wednesday. The airline said it was preparing to send an Airbus flight TG675 to Beijing to pick up the first lot of 200,000 doses from Sinovac Biotech.
Thailand has signed up for 2 million doses of the vaccine and will get complete delivery by April.
Once the first lot arrives on Wednesday, it will be checked for safety and quality before health officials start distributing it within five days of arrival.