China's cross-border e-commerce transactions increased 31.5 percent year-on-year to 2.3 trillion yuan ($375.82 billion) in 2012, a report released by iResearch Consulting Group said on Tuesday.

Despite the rapid growth, online trade volume was just 9.5 percent of the country's total import and export volume in 2012.

The group predicts that the value of China cross-border e-commerce transactions will take an increasingly large share, up to 18.5 percent of China's total import and export trade volume in 2016, reaching 6.4 trillion yuan.

China's customs administration said in February that the combined total for imports and exports in Chinese goods reached $3.87 trillion in 2012, overtaking the United States in world trade for the first time.