As product life cycle becomes less and less every day, having flexible manufacturing processes for any companies seems more demanding. In the assembling of moving part, hemming process is the one which needs more attention. This paper focused on the robot roller hemming process and system for high volume production car body line. A robot roller hemming system of hood is investigated as a case study in this paper. By applying four hemming robots, twin roller hemming head, corner hemming punch and panel location fixture, it has faster cycle times compared to convention method. As the result, it is expected that cell area, manufacturing cost of roller hemming improve as compared to press body hemming.