A method of operating a screen baseball system includes registering a personal rank of a user by a game management unit, displaying a pitching motion on a screen and starting a pitching action according to a selected pitch type, performing a simulation along a trajectory of a batted ball converted from batting detection data of a batter among users, and displaying an image on the screen by the game management unit, photographing a batting image of the batter and storing the batting image in a database by a game photographing unit such that the batting image is utilized for user training and character development programs, and transmitting simulation information and batting image data displayed, to a game shop, in which another user is positioned, in real time by a game server to play a game on line if the another user is positioned in a remote place.