Aiming to investigate senior middle school students' metacognitive learning strategies, a quantitative method is used in this study. The subjects of this research are 150 students from a private senior middle school in Zuoyun County. The theoretical model of this study is based on O'Malley and Chamot's theory of metacognitive strategies. Results show that: (1) Generally speaking, the subjects do not use metacognitive strategies frequently, they just use them sometimes; among the three categories of metacognitive strategies, evaluation and monitoring strategies are more often used than planning strategies. (2) Metacognitive strategies have a positive significant correlation with the students' English scores at the 0.01 level; they play a very important role in improving the learners' learning proficiency, among the three categories, evaluation strategies have the highest correlation with the students' English achievements. (3) High- and low-score students are significantly different in their responses to metacognitive strategies; high-score students have a better command of these strategies and they can use the strategies more effectively and frequently. (4) There is no significant difference between the male and female students in their using of planning, monitoring and evaluation strategies; namely, the male and female students are not significantly different in their using of metacognitive strategies.