CHINA'S trade surplus in August dropped from July's level due to more imports, but analysts said the pressure over yuan's appreciation was still mounting.

Last month's surplus stood at US$20 billion, down 30.4 percent from US$28.7 billion in July when it hit the highest level since February 2009, the General Administration of Customs said today.

The gap compared with US$20.1 billion in June, US$19.5 billion in May, US$1.7 billion in April, and a deficit of US$7.2 billion in March.

"Reduced trade surplus in August was mainly the result of rebounding imports last month, while exports moderated due to unstable external demand," said Xue Jun, an analyst at CITIC Securities Co.

Imports last month surged 35.2 percent from a year earlier to US$119.2 billion, up 12.5 percentage points from July. Exports, on the other hand, expanded 34.4 percent to US$139.3 billion, compared with 38.1 percent in July.

The accumulated trade surplus in the first eight months was still 14.6 percent less than the same period of last year, standing at US$103.9 billion.

However, the pressure over yuan's appreciation is still growing despite of shrinking trade surplus so far in the year as a whole.

"Countries like the United States won't stop exert political influence over China on a stronger yuan due to the need in their own markets to protect jobs and stabilize economy," said Li Maoyu, an analyst at Changjiang Securities Co.

The yuan has appreciated against the US dollar to 6.77 from 6.83, less than 1 percent since China announced to make its foreign exchange regime more flexible on June 19.