Users said they could once again reach Google, which had been barred for almost two weeks, although Altavista, another popular American search site, remained inaccessible. But now the authorities, shifting strategies, appear to be selectively blocking access to specific Google content.

Web users, no longer automatically diverted to rival search sites that adhere to the government's strict censorship rules, can now search freely on Google. But they cannot retrieve all their search results.

For instance, users searching for information on Falun Gong, the outlawed spiritual movement, turned up many references through Google. But exploring those references proved impossible, and users' Internet browsers often ceased to operate properly once an unauthorized reference had been clicked on.

And though Google users could find many articles on Jiang Zemin, China's president and Communist Party chief, they could read only the ones prepared by China's official media outlets, not those provided by opposition groups. Similar selective censorship limited the availability of Web content about Tibet.

The more nuanced approach to filtering the Internet for the country's 46 million users may reflect overwhelmingly negative reaction to blanket blockage. Chinese users, writing on Internet bulletin boards in recent days, bitterly condemned the exercise. Google is widely used to get access to an array of documents and Web addresses that use Chinese characters.

The easing could also reflect the high cost in manpower and telecommunications capacity needed to control the flow of information from the Web.

China provided no official explanation for its initial blocking of Google, and no announcement was made today either. It remained possible that Google could be completely blocked in the future, especially in the weeks before a shift in political leadership, scheduled to take place in November.