Frictional force is existed between in orthodontic bracket and orthodontic wires. Friction can be a stopper or a helper in orthodontic clinical treatment. It is a stopper when tooth is going to slide to movement. It can be a helper when tooth needed to be as anchorage. There are many factors that influence the friction. It is important to understand and apply it carefully. This paper is to discuss the friction relationship between orthodontic bracket and wire.