"There are two themes to the data," Amcham China Chairman Ted Dean said in Beijing. "American companies are doing well, and American companies are concerned in some cases about the current regulatory environment and in others the trend line for the regulatory environment."

Eighty-three percent of Amcham China member companies plan to increase investment in the country this year, according to the survey, which used responses from 434 member companies out of a total of about 1,100 members.

Some 85 percent of respondents reported increased revenue from their China operations last year. Sixty-three percent reported improved operating margins, compared with 44 percent who said the same of their 2009 results.

Seventy-one percent of the respondents said China's business licensing process discriminates against foreign companies, according to the survey. More respondents - 31 percent - named bureaucracy as one of their top five challenges, up from 23 percent in 2010.

Yao Jian, a spokesman for China's Commerce Ministry, told reporters on Tuesday in response to the Amcham survey that China will give equal treatment to foreign companies and further promote opening of the domestic market.