In this paper, the architecture of Hazard Control Systems (H. C. S. 's) for mobile robots is discussed based on an A-C Model H. C. Conceptual Design Method. First, two hazards that are typically produced in mobile robot systems are identified. These hazards are"Robot Collision against a Mobile Object". Second, Hazard Restrant Principle (H. R. P) 3 is applied to mobile robot systems for conceptualization of H. C. S. 's involve the following dissociation forms: 1) Stop by braking; 2) Stop by braking control against skid; 3) Stop by multicontrol against turnover; 4) Course control against a single static object ; 5) Course control against multiple static objects; 6) Multicontrol against multiple mobile objects. Then, the applicability of Danger-detection Information Processing Systems or Safety-confirmation Information Processing Systems is examined. Last, the relationships among whole-hazard space, the subhazard spaces where the identified hazards exist, the subhazard spaces where these Information Processing Systems are applicable in principle, and the dissociation forms are represented schematically.