The 2010 surplus was more than 2.5 times higher than the previous year at 6.77 trillion yen ($82 billion), the finance ministry said, reflecting an overall pick-up in trade from the depths of the financial crisis.
Exports rose for the first time in three years, growing 24.4 percent in 2010 from the previous year to 67.41 trillion yen.
The data also illustrated Japan's reliance on key trade partner China, whose double-digit growth last year put it on track to eclipse the island nation as the world's second-biggest economy in nominal terms.
China's strong demand for cars and semiconductors boosted exports from Japan nearly 28 percent to a record 13.09 trillion yen in 2010.
The trade surplus grew 34 percent to 727.7 billion yen in December, larger than the market forecast of 474.8 billion yen.