An International Olympic Committee spokesperson called it a "good sign", after complaints about internet access.
Some journalists arriving to cover the Games complained when they found a number of websites at Olympic media centres were blocked.
The IOC promised to take the matter up with the organising committee for the Beijing Games (Bocog).
The BBC's Chinese-language website was among many websites that were blocked by the authorities in China, but it now appears to have been made accessible - a decision welcomed by the head of the BBC's Chinese service, Lorna Ball.
"This is a great opportunity for us to show Chinese readers what first-class journalism we can deliver," she said. "But of course we will also want to check if the site is still available after the Olympics have ended." The BBC's English-language website was unblocked in China in March.
China has long prevented its citizens accessing websites it considers sensitive, but the issue has come to the fore over the last few days. Thousands of journalists arriving in Beijing to cover the Olympic Games found they could not log on to certain sites. These included news sites such as Hong Kong newspaper Apple Daily, and the websites of human rights groups like Amnesty International. Websites promoting independence for Tibet were also blacklisted.
This appeared to contravene a pledge by both the IOC and Bocog to allow journalists full access to the internet during the Olympics. On Wednesday, the IOC said it would take the matter up with Bocog. Now, the BBC Chinese-language website has been unblocked in China, although other websites remain unobtainable.
The website for the Chinese-language version of Wikipedia also appears to be available. It was unobtainable at Olympic sites on Wednesday, but available in China on Thursday.
An IOC spokeswoman told the BBC that the Olympic organisation had been in talks with Bocog since Wednesday about blocking journalists' access to the internet. "This is a good sign. It's a work in progress. These are initial, encouraging signs," said the official, talking about the apparent access to the BBC site.
The Chinese government does not usually comment about which sites it blocks and why.