The importance of mutual investment and opening-up between China and Germany is on the rise, said Ulrich Caspar, president of Frankfurt am Main Chamber of Commerce and Industry.

Germany is China's most important trading partner in Europe, and China has been Germany's top trading partner for many years, he said on Tuesday at an event in Frankfurt to promote trade and investment between Germany and Guangzhou, the capital of Guangdong province.

China and Germany should continue to open up the trade boundary. China's trial visa-free policy for ordinary passport holders from Germany, which was implemented late last year, is a positive signal, he said.

China and Germany have broad consensus, mutual interests, and an overall prospect for cooperation in green development, smart manufacturing, and bio-medicine, said Huang Yiyang, Chinese consul general in Frankfurt.

Guangzhou and Frankfurt became sister cities in 1988. Trade between Guangzhou and Germany amounted to 42.8 billion yuan ($5.95 billion) last year, up 16.1 percent year-on-year.

A total of 229 German companies are operating in Guangzhou, including Siemens, Bosch and ZF group.