The steady growth of foreign direct investment into China should say a great deal about the attractiveness of the rapidly growing Chinese economy.

But if there is a significant rise in the proportion of foreign businesses that feels they are increasingly unwelcome in China's market, it might be more about the change of investors' perception rather than China's opening up policy.

A recent survey by the American Chamber of Commerce in China showed that the proportion of US businesses that feels unwelcome to participate and compete in China's market rose to 38 percent in February, up from 26 percent only two months before. It's the largest increase since the survey started four years ago.