The strong performance of Chinese banks during the current economic boom should not make them over-confident, Zhou Xiaochuan, governor of the People's Bank of China, said on Thursday.

"With the Chinese economy growing rapidly in recent years, some banks have been enjoying high profitability and improving all their performance indicators very quickly," the central bank chief told a financial forum.

"Under these circumstances, one should be particularly aware that the economy has its own ups and downs. There are always some good times in the economic cycle, but also some bad times," he said.

"Only if you can withstand the impact of a downturn can you say your capacity has really improved," he added.

Zhou said his talks with euro zone officials this week had been friendly and had produced some good results. He did not elaborate and did not touch on monetary policy or currency issues during his speech.