China has raised its first quarter's annual economic growth rate to 9.8 percent, from the preliminary9.7 percent, according to revised statistics released by the National Bureau of Statistics (NBS) on Monday.

This was the first time for China to make such a revision, the NBS said.

According to the revised statistics, China's GDP (gross domestic product) in the first quarter grew 9.8 percent over the same period last year to 2,712.8 billion yuan (328 billion US dollars), 2.2 billion yuan greater, or 0.1 percentage points higher, than the preliminary figure.

The NBS experts explained readjustment in transportation, warehouse, post, communications, and other service industries raised the tertiary industry growth rate by 0.3 percentage points, or 2.2 billion yuan, in the first four months.

The revised statistics show that the added value of the tertiary industry reached 946.5 billion yuan in the first quarter, up 8 percent year-on-year, while other industries showed no changes.

Statistics show that China's economy grew at an annual rate of 9.1 percent last year.

The NBS published a regulation on the reform of China's GDP accounting and data release system last year in a bid to make its GDP figures more objective and truly reflect China's actual situation in its economic development, and to increase the figures' transparency and credibility.

Compared with traditional practices, the regulation changed the original quarterly GDP accounting to three steps, namely, preliminary accounting, preliminary check and final check.