BEIJING, OCT. 21 -- China's top leaders, now facing a crucial Communist Party congress, are being served for the first time with western-style public opinion polls to tell them what the Chinese people think of their policies.

In a country where the party is supposed to embody the opinion of the masses, party officials once viewed such polls as a contemptible "bourgeois" test of popular sentiment.

But in order to deal with a changing and more complex society, China's leaders are seeking a sounder basis for understanding what goes on in the minds of ordinary citizens.

The results of polls made public so far have been largely predictable and, in some cases, suspiciously supportive of existing party policies. But there have been a few surprises. A survey conducted in the city of Tianjin showed that a large number of people had no faith in Chinese politics and could not remember the names of the politicians for whom they voted in local elections.

A national survey published recently seems to indicate that a large number of people throughout China share an uncertainty about the country's political future, a finding that will not please party leaders.

In late 1986 and early 1987, student demonstrators calling for democracy shocked the party leadership and dramatized the gap in thinking between many leaders and the country's most educated youths. Even before the demonstrations, reformists in the party leadership made clear that they wanted to hear a broader range of opinion before making decisions affecting the entire country.

The party is discovering, however, that taking the pulse of more than a billion people is a difficult task. Many Chinese, fearing trouble from the authorities, have a tendency to lie or to give a safe answer to interviewers, according to Chinese researchers directing several recent polls. Moreover, Chinese pollsters tend to avoid dealing with most controversial issues.

Wu Xin, a mathematician who has directed several surveys, said China's pollsters received their original inspiration from Deng Xiaoping and his advocacy of "seeking truth from facts." Wu, 34, a deputy division chief at the National Research Center for Science and Technology, said he and his colleagues have studied western methods of polling, such as those used by American George Gallup.

But Wu said it would be wrong for China simply to copy western methods. For one thing, he said, it is more difficult for interviewers conducting polls in China to obtain direct and honest answers because the Chinese are innately cautious and suspicious.

"Most Chinese are inconsistent between what they say and what they actually do," said Wu. "Researchers in Taiwan have done studies pointing to the same conclusion."

"They might say they are enthusiastic, for example, about participating in politics, but when it comes right down to doing it, they don't participate," Wu said. "Westerners are more consistent between what they say and what they do."

Wu said his research center is trying to develop surveys to deal with this problem.

His research institute is affiliated with the government's Science and Technology Commission. But those conducting interviews in the provinces are not government employes, he said. They are mostly young people hired on a contract basis to give them semi-independent status and to lessen the chance that people will be intimidated when they are interviewed. Those being interviewed are promised that their names will not be published.

One recent survey dealt with how Chinese view themselves. Based on interviews conducted with more than 4,000 people in 42 cities, the survey is supposed to represent the views of the country's urban population.

It showed many Chinese to be conservative, or traditionalist, in that they lacked a sense of adventure and competitiveness.

The China Daily, an official English-language newspaper, concluded that the Chinese national character does not accommodate easily to modernization.

"The surveyors say the current Chinese national character remains largely traditional and passive, which inhibits individuality and initiative," the paper said.

Until recently, leaders relied on nonstatistical means of gathering views from the grass roots, such as reports from lower-level party officials, confidential reports from government news and intelligence agencies, infrequent personal visits to the provinces by the leaders and digests of letters sent in by readers to leading Chinese newspapers.

The serialized and highly classified digests of letters are distributed to the leadership in the form of confidential documents.

But the letters seem inadequate in an age of statistics. A country that was once notorious for padding its production figures now demands more honest statistics.