American football players are required quick judgment in the game. For the training of the quick judgment, American football teams analyze games of the opponent team with video and reproduce the same situations in the games according to the analysis. The training needs many players and consumes much time. In this paper, we propose a VR American football simulator with a large cylindrical screen. The large cylindrical screen gives the user immersion in a VR space. In this system, the user can watch reproduced plays from any positions. The contents of the simulation are produced simply with a video analysis tool. This system gives American football players an indoor field for training of the quick judgment in the game.