In 2002, Anderson states that metacognitive strategy is an advanced learning strategy to ensure the success of learning activities。 Proper use of learning strategies can not be neglected in the positive effects of language learning and the training of the strategies can be included in teaching process。 Furthermore, Paris and Winograd (1990) said that teachers can increase students' metacognitive awareness by means of metacognitive strategies and scientific discussions, which can provide two merits: 1) the teacher conveys the responsibility to students to monitor their learning, and 2) students develop positive self-perception and motivation。 Consequently, since the 1980s, there have shown up a large number of research studies on metacognitive strategies as well as the classifications of metacognitive strategies。

(1) Oxford's Classification (1990)文献综述

Oxford (1990) proposed a training model in his book "Language learning strategies:What every teacher should know" that includes eight steps: 

a。 Be clear to the needs of students;       

b。 Select the necessary training strategies; 

c。 Think the significance of strategy training;       

d。 Consider motivation factors of training; 

e。 Prepare materials and design activities;       

f。 Implement a complete strategy training; 

g。 Evaluation strategy training; 8) Adjustment strategy training。 

(2) Cohen's classification (1998) 

Cohen (1998) advocates a strategy-based foreign language teaching model in his "Strategies in Learning and Using Second Language", which aims to enhance students' awareness of strategy use, thus leading to a effective foreign language learning。 He proposed five steps of this strategy training model: The teacher may 

a。 use learning strategies in the process of learning, demonstrate and make examples。

b。 give more examples of the use of strategies according to their own learning experience。

c。 guide the students in groups or the whole class to discuss strategies。

d。 encourage students to practice and use a variety of strategies。

e。 combine strategies with classroom learning materials to embed strategies explicitly or implicitly into language tasks, giving students the opportunity to practice strategies in specific contexts。