As China's President Xi Jinping continues to push a sweeping campaign against official graft, a survey of American business shows corruption is a big concern for companies. The problem of corruption and fraud is one of the top five challenges for American companies in China, says the "China Business Report 2013-(2014)," released Feb 25 by the American Chamber of Commerce in Shanghai and Control Risks, a business advisory group. Eighty-two percent said the frequency with which they encounter corruption and fraud was at the same or a higher level than the previous year.