In recent years, M- teaching and learning has become popular all over the world, but there is no unified definition on it. As a kind of new teaching mode, M- teaching and learning has many advantages, such as the effective use of fragment time, increasing students' autonomy, closing the distance between students and educational resources; but it also has many disadvantages, such as the imbalance between teaching design and new technology, the difficulty in adapting to the new technology, and the imbalance between learners' individuality and generality, etc. It is suggested that M- teaching and learning can be made into full play by changing the endogenous and exogenous variables of M- teaching and learning and adjusting and optimizing it from different aspects.