China's imports and exports were valued 31.11 trillion yuan ($4.29 trillion) in the first three quarters of the year, up 9.9 percent from a year ago, data from the General Administration of Customs showed on Monday.

The exports increased 13.8 percent year-on-year to 17.67 trillion yuan, while the imports totaled 13.44 trillion yuan, rising 5.2 percent on a yearly basis.

The trade surplus during the period reached 4.23 trillion yuan, surging 53.7 percent year-on-year.

In September alone, the combined import and export value was 3.81 trillion yuan, rising 8.3 percent from a year earlier.

The exports were valued 2.19 trillion yuan, growing 10.7 percent year-on-year, and the imports increased 5.2 percent from a year ago to 1.62 trillion yuan.

Trade surplus in September was 573.57 billion yuan, expanding 29.9 percent year-on-year.