Abstract
This research adopted a research method called thinking-aloud to study what strategies are used by ten Chinese EFL learners when they tried to understand the meaning of 20 English idioms. Data revealed that subjects usually employed more than one single understanding strategy in interpreting the meaning of an English idiom and that context played an important role in the whole process of the subjects’ interpretation.
Keywords   English idioms   understanding strategy   context

 本文通过有声思维的方法，收集了十名中国的英语学习者对20个英语中常用习语的理解加工策略。数据分析并揭示了这些受试者对英语习语的理解是通过对多种策略的综合使用来实现的；而上下文则充当着习语理解过程中的必要条件的重要作用。
关键词  英语习语   理解策略   上下文 

An idiom (Latin: idioma, "special property") is an expression, word, or phrase that has a figurative meaning that is comprehended in regard to a common use of that expression that is separate from the literal meaning or definition of the words of which it is made(The Oxford Companion to the English Language,1992,pp.495–96). There are estimated to be at least 25,000 idiomatic expressions in the English language.
In linguistics, idioms are usually supposed to be figures of speech contradicting the principle of compositionality; yet the matter remains debated. In phraseology, they are defined in a similar way as a sub-type of phraseme whose meaning is not the regular sum of the meanings of its components. John Saeed (Semantics, 2003, p.60) defines an "idiom" as words collocated that became affixed to each other until metamorphosing into a fossilized term. This collocation—words commonly used in a group—redefines each component word in the word-group and becomes an idiomatic expression. The words develop a specialized meaning as an entity, as an idiom.