BEIJING, Oct.13 -- The depreciation of the Chinese yuan has limited impact on boosting China's trade, a senior customs official said Thursday.

Chinese yuan depreciation might benefit domestic exporters, but would also raise the import costs of production materials as processing trade still remained a major part of of China's trade pattern, said Huang Songping, spokesperson with the General Administration of Customs (GAC) at a press conference.

An economy's currency fluctuations could have a mixed impact on trade growth due to cross-border cooperation along the global industrial value chain, undermining the boosting effects for exports, Huang added.

China's exports in yuan-denominated terms fell 5.6 percent year on year in September, while imports increased 2.2 percent, customs data showed Thursday.

The Chinese yuan continued a weakening streak against the U.S.dollar after the renminbi was officially included in the SDR currency basket on Oct.1.

The entry would allow exporters to use the renminbi as a pricing currency during trade and cross-border investment and help reduce foreign exchange rate fluctuation risk and exchange costs, Huang said.