This paper presents a novel observation system for immersive soccer match taken by multiple video cameras at a real stadium. The user sees the soccer field model in front of his/her eyes from the viewpoint through head-mounted display, while the images of players and a soccer ball are also rendered onto the display. For geometric registration between the soccer field model in the real world and the dynamic soccer scene in the rendered images, the viewpoint position of the user is computed by using only natural feature lines in the HMD camera image. Since it is difficult to strongly calibrate the HMD camera and the multiple cameras that capture the real soccer scene, we employ projective geometry for the registration and the rendering. For demonstrating the efficacy of the proposed system, video images of soccer matches taken at real stadium are rendered onto the HMD camera images of a tabletop stadium model. This is a completely new challenge to apply augmented reality to a dynamic event in a large-space.