Thai exports to China will likely shrink by 117 billion baht over the next five years as a result of liberalisation under the Asean Economic Community.
Starting next year, Thai exports to the mainland will face intensifying competition from CLMV countries - Cambodia, Laos, Myanmar and Vietnam - although Thailand's market share in China will increase slightly to 1.97% by 2019 from 1.95% at present.
Aat Pisanwanich, dean of the Economics Faculty at the University of the Thai Chamber of Commerce, revealed the study's findings on Tuesday.
Electrical appliances and electronics will likely be hit the hardest, with export value expected to shrink by 198 billion baht. Malaysia, a former regional market leader, has expanded shipments while Vietnam saw more investments for exports.
Farm products and aquatic animals will be increasingly affected. Thai rice exports to China will fall by 14.6 billion baht while the product's market share in China will contracted to 20-30% from 90%.
Labour-intensive businesses such as textiles, apparels, footwear and jewellery will also suffer.
Thai products to benefit from the AEC are tapioca, rubber and rubber products, processed food, wood and wooden products and plastics.
"Thailand is now No. 2 Asean exporter in China after Malaysia. But over the next five years, our export value will slide to No. 4, overtaken by Indonesia and Vietnam. The same also applies to our intra-Asean trade," Mr Aat said.
"A way out is to add value to products and improve quality," he said.
Thai exports this year will grow by less than 1% but is unlikely to contract thanks to more imports ahead of the festive season. For next year, they may grow by 4% in line with the world economy.
Risk factors next year are the fledging economies of the euro zone and China, unrest in Russia and the weak baht, which may depreciate to 31-32 to the US dollar.
Mr Aat suggested the government coordinate to set up distribution centres for Thai products in China which can double as research centres for local demands.
With more data, Thai operators can focus their limited resources more effectively on specific regions in the mainland.
China is Thailand's largest export market, accounting for 10.9% of total shipments worth 5.47 trillion baht in the first nine months of this year, followed by the United States (10.3%), Japan (9.7%), Hong Kong (5.7%) and Malaysia (5.6%), according to commerce ministry data.