A score verification system for verifying that a score of a player having played an online game is a true score of the player. A player terminal receives a game program from an online game server, and the game is played on the player terminal. Plural players execute the same online game, and compete for high score. The score acquired by the player, together with an operation history of the player, is transmitted to the online game server. In the case where the score may be a high score, the same play is reproduced based upon the operation history received by the online game server, and the fairness of the received score is verified based on the score obtained by the reproduction.