The registry, containing domain names and addresses, began operation Thursday, ITAR-Tass reported Monday.
About 3,000 complaints about Internet sites were filed with the registry on the first day.
Three federal watchdog agencies for monitoring drugs, consumer rights violations and communications are responsible for deciding what Internet resources or content will be put on the blacklist.
Materials considered extremist by Russian authorities, including anti-clerical works by Leo Tolstoy and works of classic Russian and foreign literature, also were added to the blacklist.
A listing of banned sites and content is not available to the public, but the registry can be searched to see if a specific site has been banned.