Vocabulary is very crucial to language because without words, language has no meaning at all. There has been a history of thousands of years of research on vocabulary acquisition and teaching, however, language teachers are still facing a huge challenge now, that is how to help students acquire the words quickly and effectively. This paper puts forward cognitive teaching strategy which has a new approach into vocabulary teaching. The purpose of this study is to examine the effects of cognitive linguistic approach in teaching English vocabulary at a public university in Vietnam. A total of 35 students participated in this study. The instruments of the study were pre-test, post-test. The study showed that CLA can give an effect on teaching Vocabulary because the score of students’ vocabulary after being taught CLA was higher than before applying CLA in the class. It is hoped that this study would offer educators and researchers a practical teaching strategy for increasing students' vocabulary in language classes.