The nation's current account surplus in February rose 29.6 percent from a year earlier to ¥1.471 trillion, underpinned by growing demand for Japanese products overseas, Finance Ministry data showed Thursday.
It marks the seventh straight month of year-on-year improvement in the current account balance.
Many economists predict the economic recovery will continue in the months ahead on brisk exports, especially to China.
Japan has seen a current account surplus for 13 straight months.
The balance of trade in goods and services posted a surplus of ¥693.4 billion, up from ¥69.3 billion a year before, the Finance Ministry said in a preliminary report.
The surplus in merchandise trade surged 295.1 percent to ¥778.0 billion.
Exports jumped 47.3 percent to ¥4.866 trillion, the largest expansion since comparable data became available in 1986.
The third straight month of growth was led by increases in shipments of cars, machinery and high-tech devices to Asia and North America.
Imports expanded for the second month running, up 31.6 percent to ¥4.087 trillion, partly because of rising oil prices.
Atsushi Matsumoto, an economist at Mizuho Research Institute, said a weakening of the yen in recent weeks is an additional positive factor for the ongoing export-driven recovery.
"It is likely that exports will stay firm for at least six months," Matsumoto said. "But it remains to be seen whether the trend will carry on after around October. That largely depends on the course of China."