The plane, which had flown in from the Chinese city of Nanjing, took off shortly after 11.30am (4.30am GMT) for the border city of Xishuangbanna.
A Thai border task force official told AFP that 200 more Chinese nationals are expected to be returned on Thursday, crossing from Myanmar in groups of 50.
China has arranged 16 flights over the next three days to ferry 600 of its nationals home from Mae Sot.
It is not clear what fate awaits them, but Chinese security personnel are expected to accompany the returnees on the planes.
The Karen Border Guard Force (BGF), a militia allied with the Myanmar junta, has said it is preparing to deport 10,000 people linked to the compounds in areas it controls on the border with Thailand.
“Two hundred Chinese nationals involved in online gambling, telecom fraud and other crimes were handed over in accordance with legal procedures through Thailand this morning, in the spirit of humanitarianism and friendship between countries,” the Myanmar junta said in a statement.
