Hong Kong outperformed Japan in 2012 and became the mainland's fourth-largest trade partner.

Bilateral trade increased 20.5 percent year-on-year in 2012 to $341.49 billion, accounting for 8.8 percent of the mainland's total foreign trade last year, Zheng Yuesheng, spokesman of the General Administration of Customs told a news briefing on Thursday.

China's trade with Japan, its fifth-largest trade partner, decreased 3.9 percent year-on-year to $329.45 billion in 2012, making up 8.5 percent of China's foreign trade, as territorial tensions continue between the world's second and third-largest economies.

China's trade with Russia increased 11.2 percent year-on-year to $88.16 billion in 2012, while trade with Brazil rose 1.8 percent to $85.72 billion, Zheng said.