TG theory is a brand-new theory founded by Noam Chomsky, a very famous Americanlinguist, in 1950s. It is one of the two most influential linguistic schools in the present world.Based upon rationalism, TG theory advocates inference and reasoning, thus opposing the rigidimitation and the mechanical memorizing of the grammatical rules of the target language, which were initiated by the traditional methodology of behaviorist structuralism. After a brief review of TG's developing history and its theoretical and philosophical foundations, this article, from different angles, has illustrated the advantages of TG theory used in English teaching through concrete examples.