Abstract: Many non-English major college students with poor reading ability take vocabulary as the primary reason. The experiments concerned also shows that the comprehension of a reading passage is highly related to the size of the reader's vocabulary. In fact, vocabulary not only can affect the reader's processing and retrieving of information from the brain but also can have an influence on the reader's effective operation of the short-term memory system, thus affecting his reading. To improve the student's reading ability, English teachers should take effective strategies to help students broaden and deepen their vocabulary.