An important problem of mobile robots is to determine an obstacle avoidance control which transfers the system along a collision-free path among obstacles in environment. Two kinds of method are used to solve the problem. One is to track an already planned path which is created by high-level path planning system, the other is so called feed-back path control. It makes use of an abstract force in artificial potential field to control robot motion.According to the second method, we present a dynamic path planning and control method. It is suitable to navigate mobile robots in real time.The stability of the system and the adaptability are increased.