It said it would investigate how the feature was being used by advertisers.
News organization ProPublica discovered that the system could be abused by posting discriminatory ads on the social network.
Facebook said it would look for a way to change the system so it could not be used "inappropriately".
Last year, ProPublica first discovered the ethnic discrimination via advertising was possible.
US laws prohibit discrimination in the way ProPublica demonstrated - in adverts relating to housing, for example - was possible.