A group of well-known scholars in China, such as Wen Qiufang (1995), Wu Yi'an (1993), Cheng Suping (1996) and Deng Xiaofang (2004) have done a lot of researches on metacognitive strategies and achieved a lot in this field. The fruits and achievements have had a profound influence on both the theory and practice of foreign language learning and teaching. Wen Qiufang (1995) points out that, during the learning process, excellent students can have a good command of all strategies effectively and they always reflect what they have achieved as well as the strategies they have used in learning. Actually, Wen Qiufang's (1996) concept of management strategies in the analysis of learning strategy is equal to what O'Malley and Chamot (2001) called metacognitive strategies. Liu Peihua (1998) also believes that metacognition has a positive effect on language learning. As the description above shows, metacognitive strategies are pivotal to the success of a learning activity. Therefore, it has become a new focus in language learning and teaching. Many empirical studies on it have been conducted on the basis of relevant theories. However, Wen Qiufang (2003) considers the research on metacognitive strategies in China is still weak. There is also a fact that in the research of metacognitive strategies, most researchers in China do not pay much attention to middle school students, they are only interested in college students. Therefore, the author of this paper attempts to investigate the general situation of metacognitive strategies of senior middle school students with a quantitative research method and aims to improve their English achievements. What makes this study different from others is that its theoretical model is based on O'Malley and Chamot's theory of metacognitive strategies.