From April to August 4, the trade volume passing through the Myawaddy border with Thailand reached US$280 million, down US$10 million compared with the same period last year.
Trade had been increasing since the Asia Road opened but both imports and exports declined since June.
Exports were a tiny US$18 million while imports amounted to US$262 million.
Imports include food, beauty products, personal goods, machinery, farm equipment and vehicles from Thailand, re-exports fertilisers and sugar to China and exports marine products, food and traditional medicine to Thailand. Plans are under way to officially export maize.
Through the 16 border trade camps, the country's exports exceeded imports everywhere other than Myawaddy, where imports were on average 13 times higher, the authorities said.