Adith Chairattananon, secretary general of the Association of Thai Travel Agents, said there is a 20% drop in Chinese tourist arrivals during the Thai New Year compared to last year, Nation Thailand reported.
All charter flights from Chengdu City have been canceled, he added.
The Thai government has said the Songkran celebrations, a week-long public water fight meant for ritual cleansing, starting in mid-April would go ahead as planned in Bangkok, Chiang Mai and other locations.
Industry insiders have urged the government to quickly take action to head off public fears.
Myanmar's strongest earthquake in 100 years on March 28 sent tremors across Bangkok and parts of Vietnam and China. Many foreign tourists in Bangkok were left shaken as tremors swayed high-rise buildings, cracked walls and caused water to spill from rooftop swimming pools.
Nguyen Thuy Trang of Hanoi, who had booked an air ticket to Thailand, visited dozens of Thai travel forums over the past two days to gauge the situation and seek advice on whether to go ahead with or cancel her planned trip.
In the end she decided to cancel her trip to Bangkok due to growing safety concerns.
"The number of customers booking tours for Songkran this year is lower than usual because of safety concerns after the earthquake," Nguyen Huu Cuong, general director of Trang An Travel, said.
Pham Anh Vu, deputy general director of Du Lich Viet, said some customers have rescheduled their itineraries for May or latter.
Thailand could see a 10-15% drop in foreign arrivals over the next two weeks for the Songkran festival, Thienprasit Chaiyapatranun, president of the Thai Hotels Association, said in a statement, Bloomberg reported.