Based on the analysis of expressional forms of vague language, the paper probes into and summarizes the following communicative functions as courtesy and respect, exactness and credibility of language, modesty and self-protection.

• 本文从对模糊语表现形式的分析入手，探讨和总结了模糊语在医学英语中具有体现礼貌和尊重、语言的准确性和可信度、谦虚和自我保护等交际功能。