— In this paper, we describe the real-time and precise self collision detection system that does not reduce the number of polygons and checks more than 100 collision pairs in real-time by using AABB based collision detection libraries. Previous researches on collision detection of humanoid robots which reduce collision pairs or simplify a shape of a robot has disadvantages such as increasing the dangerousness or decreasing range of movement. However our self collision detection system uses detailed geometric model and collision pairs as many as possible. We have experimentally evaluated collision detection libraries on a real-time self collision detection application of a humanoid robot. This experiment suggests that AABBs based method is much faster than conventional OBBs based method. Finally, we demonstrated real-time collision detection and avoidance function that automatically stops entire motion if self collision occurs using HRP2 humanoid robot.