China's net imports of crude oil rose 11.5 percent from a year earlier to 65.83 million tons in the first five months of the year, driven by the country's robust economic growth.

From January to May, China imported 67.43 million tons of crude oil, up 9.6 percent year-on-year and exported 1.6 million tons, down 36.6 percent, according to the latest statistics from the General Administration of Customs (GAC).

"China's rapid economic growth, especially its expanding oil refining capacity, contributed to the rise in crude oil imports," said Tian Chunrong, a researcher with the China Petroleum and Chemical Corporation.

The country refined 133 million tons of crude oil in the first five months, up 6.5 percent year on year, as shown in figures from the National Bureau of Statistics (NBS).

Last November, China levied a five-percent export duty on crude oil causing the sharp drop of oil exports, said Tian.

According to GAC statistics, the country imported 14.79 million tons of refined oil products between January and May, up 4.5 percent from a year ago. It exported 6.47 million tons of oil products, with a year-on-year growth of 22.2 percent.

According to calculations by Xinhua based on data from the NBS, China's crude oil output rose 1.7 percent year on year to 77.51 million tons in the first five months.

"This growth rate is the same as last year's output level. Crude oil output has been growing between one percent to two percent in recent years," said Tian.

In May, China produced 16.06 million tons of crude oil, an increase of two percent year-on-year. It imported 12.97 million tons of crude oil, down slightly from 13.86 million tons in March and 14.82 million tons in April.

The country exported 520,000 tons of crude oil last month, as the monthly crude oil net imports reached 12.45 million tons.

In terms of refined oil, May's imports came at 3.17 million tons and exports 1.22 million tons.