This thesis reviews conceptual metaphor and explores its application to vocabulary teaching. Conceptual metaphor, put forward by Lak off & Johnson, is the systematic cognitive model or metaphorical process of thinking that lies behind much of everyday language and structures our conceptual system. According to Lak off & Johnson, the essence of metaphor is to understand or experience one thing in terms of another, so the application of metaphor to vocabulary teaching can help students to master metaphorical expressions and use these expressions flexibly. This dissertation consists of six parts. After a brief introduction in the first part, the author introduces the historical development of vocabulary teaching in China and analyzes the difficulties in present vocabulary teaching. The author introduces the theory about conceptual metaphor in the third part, including the historical development of the theory about metaphor nd its characters. The fourth part sums up the relationship between metaphor and vocabulary teaching and puts forward the possibility of applying conceptual metaphor to vocabulary teaching. The fifth part deals with application of metaphor to vocabulary teaching in two aspects. One is the teaching of metaphorical meaning of vocabulary; the other is the use of metaphorical expressions. Mechanism of metaphor can give a good explanation to the extension of the word meaning. And cultural knowledge is indispensable to the comprehension of metaphorical expressions. When students use metaphorical expressions, they have to pay attention to context constricution. More important, students need comprehend synthetically all metaphorical concepts related to one subject and words and expressions related to one metaphorical concept, so that they can use metaphorical expressions flexibly. The results of survey about metaphorical expressions are provided at thd end of the dissertation. It is the preliminary attempt to apply metaphor to vocabulary teaching. In the last part, a conclusion is drawn that the function of conceptual metaphor in foreigh language teaching is worth further study, and some ideas in this area for further study are suggested.