Google's English-language website is running normally in China after being inaccessible for more than two hours yesterday, according to state media.
Observers speculated that the outage was connected to state pressure on Google to stop porn appearing on its Chinese site.
Google has not commented on the outage, but announced yesterday that it had re-engineered the site to meet the demands of Chinese authorities.
The move comes after Google promised last week to work harder to eliminate pornography after complaints by a Chinese government Internet watchdog.
Earlier this month the Chinese government said every PC in the country must be sold with software that can block access to online pornography from next month.
The move has raised concerns that China could be trying to take its internet censorship to a new level by using the software to block all information critical of authorities.