(Adds comments from Pew's Wike)
BEIJING, Oct 16 (Reuters) - Weeks before China unveils its next generation of leaders, a new survey has found that growing numbers of its people worry about corruption, inequality and food safety, while ties with the United States are increasingly viewed with suspicion.
The latest Pew Global Attitudes China Project, which polled more than 3,000 people earlier this year, shines a rare light on public opinion in a country where the government attempts to control information and limit discussion of contentious issues.
The survey, released on Tuesday, comes ahead of a Communist Party congress starting on Nov. 8, where those who will hold power for the next decade will be announced.
"As China prepares for its once-in-a-decade change of leadership, the Chinese people believe their country faces serious and growing challenges," the authors of the survey wrote.
"In particular, the side effects of rapid economic growth, including the gap between rich and poor, rising prices (and) pollution ... are major concerns, and there are also increasing worries about political corruption."
Graft is a particular sore point for leaders of the world's second-largest economy. The Communist Party has repeatedly warned that anger over corruption could threaten its survival, or at least destabilise its tight hold on power.
Half the respondents said they thought corrupt officials were a very big problem, up 11 percentage points from four years ago, while one-third thought corrupt business people were a major concern, up from around one-fifth in 2008.
Many Chinese have been enraged this year by a string of incidents of corruption and misuse of power, including a high-speed Ferrari crash reportedly involving the son of a senior official and a local official photographed flaunting luxury watches beyond the reach of his salary.
More sensationally, Bo Xilai, the former Communist Party chief of the city of Chongqing and a one-time high-flyer, was sacked this year on charges of graft and bending the law to hush up the murder of a British businessman by his wife.
One of the most dramatic shifts in public opinion was over food safety; respondents rating it a very big problem jumped almost 30 percentage points from 2008 figures, underscoring the impact of repeated food scandals on public confidence.
Chinese media report on food adulteration cases almost every day, including the scourge of old cooking oil dredged from gutters to be re-packaged and re-sold, and the regular tainting of dairy products with poisonous substances.
The findings are part of ongoing research in China that has gone on for years, said R ichard Wike, associate director of the Pew Research Center's Global Attitudes Project.
"We've reported survey results from China for a decade, and we expect to continue," Wike told Reuters.
The Pew group purchased the data from Beijing-based Horizon Research Consultancy Group, he said, adding that Pew works with Princeton Survey Research International to find reliable local research partners for its global surveys.
Inflation remained the biggest worry in the survey although fewer Chinese now view prices as a very big problem compared with four years ago. But a still significant six-in-10 rated it a top worry, down from more than seven-in-10 four years ago.
The party views inflation as a social ill which also has the potential to undermine its grip and legitimacy.
The annual rate of headline inflation has eased since hitting a three-year high of 6.5 percent in July 2011, dropping well below the government's 4 percent target to 1.9 percent in September. Food prices - an area of sensitivity given the country's relatively low incomes - are still running at an average 5.5 percent higher than last year.
The rich-poor divide is another area of concern for the government, and Pew found that almost half of Chinese rated it a top worry.
Diplomatically, Chinese are also more pessimistic about relations with the United States, the survey found, as arguments over everything from Tibet and Taiwan to the value of China's yuan currency took their toll.
The percentage of Chinese who characterised ties with Washington as "one of cooperation" sank to 39 percent from 68 percent in a previous survey.
But half of respondents said they like "American ideas about democracy", up four percentage points.
"Many Chinese - especially younger, wealthier, well-educated, and urban Chinese - continue to embrace certain elements of American soft power. In particular, many admire the United States for its scientific and technological achievements," the authors wrote. (Reporting by Ben Blanchard; Additional reporting by Nick Edwards in Beijing and Susan Heavey in Washington; Editing by Raju Gopalakrishnan and Cynthia Osterman)