When asked if it had banned the words 'freedom' and 'democracy' from the web portal, which was launched last month, the company said it had a list of words that kept content within the norms of the country.
In an e-mail sent to silicon.com, Microsoft said: "We don't disclose the list but we do have the ability to change and update the filter as needed to help ensure we abide by the laws, regulations and norms of China."
Microsoft dodged the question of censorship earlier this week, after an article in the Financial Times accused it of scrubbing the words 'democracy' and 'freedom' from the Chinese version of its MSN website.
According to the FT, the MSN site blocks anti-communist phrases by sending an error message to anyone using the words, to avoid upsetting the Chinese government.
The error message is reported to say: "This item contains forbidden speech. Please delete the forbidden speech from this item." The Chinese words for 'demonstration', 'democratic movement' and 'Taiwan independence' are also said to be banned.
Microsoft partnered with a state-owned company, the Shanghai Alliance Investment, last month to create the Chinese arm of MSN.
Chinese officials are currently trying to make people register websites with the state by July. If they do not, they risk being shut down.
Silicon.com's Dan Ilett reported from London. For more coverage from Silicon.com, click here.
