Along with the advancement of information technology comes the web-based college English autonomous learning approach.Influenced by the traditional teacher-centered teaching approach,a great number of learners,when set in the brand-new web-based autonomous learning environment,experience difficulties in such aspects as adopting a positive attitude,defining learning tasks,applying learning strategies,supervising their learning processes and assessing their learning results.The non-linear web-based environment tends to provoke "disorientation" among learners and thereby compromise their learning performance.Metacognition consists of an active control of the cognitive process,an all-around surveillance of the comprehension process,and a dynamic assessment of the task implementation.The learners' level of metacognition has a significant positive correlation with their English proficiency.The cultivation of metacognition can assist learners in autonomously establishing objectives,designing plans,choosing strategies,supervising their learning processes and assessing their learning results,so that a successful web-based autonomous learning would be achieved.