This paper first reveals the non-verbal behavior and then further emphasizes the important of body behavior which can be used in class frequently under the classification of the non-verbal behavior. By analyzing the important role of non-verbal behavior plays in communication, the paper discusses the specific and important part that non-verbal behavior serves, especially in foreign language teaching. The paper concludes that non-verbal behavior can perform as a relation maintainer, a structure maker, and a content container. The further suggestions for teacher to facilitate are proposed.