| Successful language learning depends on one's vocabulary in some degree, and mastering a certain amount of words is the guarantee of improving student's ability of listening, speaking, reading, writing and translation. Chinese high school students need to build a firm foundation for their further English language learning, and as a result, mastering a sufficient vocabulary is an essential task to accomplish. However, as the English vocabulary is huge in number and lack in regularity, vocabulary learning poses great difficulty for high school students. Besides, lack of self-management and self-monitoring, as well as a vague metacognitive consciousness lead to unsuccessful vocabulary learning. At the same time, lack of metacognitive strategies hinders their employment of other vocabulary cognitive strategies. With all these, high school students need to be instructed in vocabulary learning strategies, especially in vocabulary metacognitive strategy, which is an effective way to enhance students' self-management and facilitate their active development. In China, the newly published High School English Curriculum Standard regards learning strategies as teaching objectives. It has profound significance for the improvement of the students' learning efficiency and teachers' instructions. In order to have an efficient vocabulary teaching and find solutions to solve the problems that the author's students have in learning vocabulary.The author carry out an action research on applying metacognitive strategy in high school vocabulary teaching.The author first conducted a vocabulary survey in the class that the author teaches. With the data collected and analyzed, a study of vocabulary metacognitive strategy training is conducted in the former class,. The research data came from the scores of their pre- ,mid- and post-training tests, interviewing and the last survey. During the course of the research, the author makes relevant adjust according to the research result. The result of the study shows that explicit metacognitive strategy dose make significantly long and positive effect on the vocabulary learning in the author's class. |