Authorities at the airport said they could not clear the accident, and flight delays were likely Monday.
The Bangkok-bound flight, TG679, left Guangzhou at 9.25pm (local time) and was scheduled to arrive at Suvarnabhumi airport at 11.20pm, Thailand time.
The airline statement said the nose gear of the Airbus 330-300 collapsed when it touched the runway during the landing.
According to some passenger accounts, a loud noise was heard on landing and there was a fire at the right side of the aircraft.
The plane skidded off the runway, and passengers were evacuated using slides.
According to THAI, there were 288 passengers and 14 crew members aboard the direct flight from Guangzhou.
Apparently no one was hurt during the actual accident. A total of "13 passengers received minor injuries while evacuating the aircraft," the airline's statement said.
THAI president Sorajak Kasemsuvan said the airline had not moved the aircraft from the runway, which was blocked to all aircraft as of Monday morning. There was no need to switch flights to Don Mueang airport, as Suvarnabhumi could manage the situation, Mr Sorajak said.
However, some delays are expected for both inbound and outbound flights using the airport on Monday, he said.
Baggage was still on the stranded flight, as the airline has to investigate the accident and remove the aircraft before unloading.
THAI opened a 24-hour hotline for information about the accident. The number inside Thailand is 02-545-3181. From outside the country, the number is +66-2-545-3181.