Mastering grammar is the foundation in the proficiency of a language. Grammar teaching is also an essential part of language teaching. However, with the communicative approach was introduced into China, many foreign language teachers gradually make little of grammar teaching. In terms of the theory of linguistics, this paper specifically explores the status of grammar in language learning, the characteristics of foreign language learning, theoretical basis of communicative teaching approach, and the practical effect of ignoring grammar teaching to reposition grammar teaching for a comprehensive understanding of the necessity of teaching grammar.