Many studies have pointed out a proportionate relation between metacognition and reading strategies. This study advances such an understanding by arguing that this relation is comprised of several sub-relations. Metacognitive Awareness Inventory and Reading Strategies Inventory were conducted among 92 English as Foreign Language students at a Vietnamese university. This study highlights 3 major findings. First, metacognition processes do not merely mean "cognition about cognition". Second, while previous studies tended to portray metacognition as a whole, it is argued in this study that it is constituted by two main clusters (knowledge of cognition and regulation of cognition) which can be further specified into eight sub-components. Third, there seem to be some sub-linearities that underpin students' metacognition and that influence their uses of reading strategies. These findings are hoped to shed light on preserving spaces and autonomy in curriculum/syllabus development for students to exercise their own metacognition.