Abstract: This study adopts a corpus-based approach to analyze the characteristics of modal verbs' semantic meanings expressed by Chinese English-major learners. It turns out that (1) both overuse and underuse of modal verbs are co-existing among Chinese English-major learners. They overuse those modal verbs that appear earlier in textbooks and underuse those ones that can express such interpersonal meanings as politeness and mildness; (2) Learners tend to use more demonic modal sequences than epistemic ones. And, moreover, modal verbs in learners' language tend to be preceded by personal pronouns and followed by main verbs; (3) With the improvement of learners' language ability, the frequency of using epistemic modal sequences can not be improved greatly.