In this paper, a computer vision based method is proposed to deal with the problem of navigation for visually impaired people. Using the color information and the marker encoding method used in Augmented Reality, we design these color markers which can be placed in the environment. In practice, users used a Smart Phone to find the marker, and the phone will send a feedback to the users. Besides the code of the marker, we also use the data collected from Smart Phone's sensor to improve the navigation system. Experimental results show that our color marker can be used in indoor and outdoor environments and can guide the users successfully to their destinations. They reveal the validity and feasibility of the system in navigation for visually impaired people.