A ranking method and system for providing a ranking of a game group is disclosed. The method includes creating a game group including a user and at least one member among the user's registered friends who have joined a game service, based on a game group creation request received from a user terminal. The method further comprises calculating a ranking of the user with respect to other members of the created game group based on a ranking inquiry request received from the user terminal, and providing the user terminal with the calculated ranking of the user. The user terminal drives a game service platform associated with a plurality of games and provides the game group creation request information and the ranking inquiry request information through the game service platform.