The components for providing autonomous capabilities of a mobile robot are grouped into few basic modules, namely motion planner, motion executor, motion assistant, and behavior arbitrator The primitive motion executors such as obstacle avoidance, goal following, wall following, docking, and path tracking for mobile robot navigation are developed in this paper. They are integrated with motion planner, motion assistants, and behavior arbitrator together based on decentralized control architecture with a hierarchical shared information memory. Event driven concept is used on switching the motion behaviors. The resultant intelligence for mobile robot navigation is capable of efficiently performing motion behavior and detecting environmental evens in parallel to adapt dynamically changed environment. It also allows the human to program the motion behaviors in high level to complete a task. Experimental results on a real mobile robot have demonstrated the robustness of the motion executors and the overall system.