Tourist arrivals between January 1 and May 15 totalled 9.47 million, Traisulee said.
Most were from East, South, and Southeast, she added.
The Tourism Authority of Thailand has estimated that 5.3 tourists from China will visit Thailand this year, and the number could rise to 7 million.
China relaxed its strict Covid-19 measures early this year and allowed outbound group tours from February 6, leading to an influx of Chinese tourists to Thailand.
A total of 12,805 flights from China landed in Thailand in the first seven months of fiscal 2023 (October 2022 to April 2023), up by 98% year on year, Traisulee said, citing official data from Aeronautical Radio of Thailand Co Ltd, a state enterprise.
Another 5,330 flights from China are expected in May, 6,090 in June, 7,150 in July, 7,460 in August, and 7,340 in September.
Flights from China are expected to total 46,175 this year.
The number is still as much as 66% lower than the year before the pandemic, 2019.
However, Thai state agencies are working closely with aviation officials in China to increase the number of flights, Traisulee said.