Japan said its exports in September rose 14.4% from a year earlier.
The Ministry of Finance said that the value of Japanese exports expanded to 5.8 trillion yen (72 billion US dollars).
The ministry said it was the slowest month of export growth in 2010.
Exports to China, Japan's biggest trading partner, increased 10.3% in September from a year earlier.
US-bound shipments grew 10.4%, while those to the European Union rose 11.2% in the month.