Metacognition is a powerful predictor for learning performance, and for problem-solving. But how metacognition works for cognitive strategies and learning performance is not clear. The present study was designed to explore how metacognition affected the cognition (learning strategies and problem solving strategies) and different kinds of learning performance involving the development of metacognition for adolescents. In a first study, we explored the structure of metacognition by examining multiple theoretical frameworks and the psychometric characteristics of metacognition. The Bifactor model confirmed the two processes modeling of domain-general versus domain-specific monitoring for different tasks in reading and mathematics. In a second study, a path model was used to explore the effect of metacognition on learning strategies, problem-solving strategies, and performance of reading and mathematics. The relationships in the model were tested controlling gender and age. Results showed that problem-solving was the only mediator between general metacognition and learning performance. It is suggested that the subcomponents of metacognition be involved in future studies.