Cognitive theory is based on the work of psychologists and psycholinguists working on the internal factors of individual’s mind. As language learning is a complex mental process therefore the focus of cognitive learning theories is the learning process in learners’ minds. This paper aims to show that cognitive learning theories are the theoretical foundation of second language teaching and learning according to the comparison of theories between Anderson and Mc Laughlin. The comparing result indicates that cognitive learning theories play a significant role in second language teaching and learning but the learners’ external factors cannot be neglected either.