So far the students of Le Hong Phong Junior High School have been taught grammar with GTM (Grammar-Translation Method), which just prepares learners for conventional grammar-paper tests. Despite their considerable knowledge of grammar, the students fail to use the language they have learnt to communicate in real-life situations. The purpose of this study was to investigate whether the communicative grammar teaching method was effective in terms of students' grammatical knowledge and oral communication, and their attitudes towards this teaching method. The results of the study highlight the treatment on both grammatical knowledge and oral communication as well as positive attitudes from the students. These lead to two major conclusions that the communicative grammar teaching indeed helped the students improve their grammar competence and use it effectively in communication, at least in oral production. Besides, this implementation appealed the students' interest in grammar lessons.