When you mention lexicology, absolutely it is a branch of linguistics, inquiring into the origins and meanings of words. The lexicologist McCarthy (1990) have given us his opinion about it. He said, grammar is important, and it indeed plays a vital role in English study, but that is not all. In fact, tar from this. From this we can see, vocabulary and the study and learning of vocabulary take an outstanding place in the study of language, it will improve his skills of using reference books and raise his problem-solving ability and efficiency of individual study. And it will make you much more receptive and productive in language processing and lan?guage production.Knowledge of English Lexicology can offer a great help to the work of the teachers of English. Armed with this knowledge, they can better control the teaching materials, especially the concerning words. They can also select and organize mate?rials to teach in a more effective way. What is more, they can make use of the different sense relations to group vocabulary, inter?pret words and explain meanings to the students;At last, their teaching will prove better if they have the knowledge of dictionaries. In my thesis, I will talk about how to deal with new words in material.