本文利用图词干扰实验和掩蔽启动实验，通过考察不同语义相关性对英语二语词汇理解的影响，研究中国英语二语学习者语言理解中的词汇选择机制。结果表明中国英语二语学习者在语言理解中选择有独特的词汇选择机制———竞争干扰模型：竞争产生干扰，同一范畴词竞争产生的干扰效应大于非同一范畴词，同一范畴内不同语义相关程度的词竞争产生的干扰会根据语义相关性不同而变化，不同范畴词之间的相互竞争干扰随着条件的变化而不同。

With picture-word interference paradigm and masked priming paradigm, the present paper investigated the lexical selection mechanism in comprehension for Chinese learners of English through exploring the influences of different semantic relatedness on lexical comprehension. Based on the related assumptions and results, it is concluded that the lexical selection in comprehension for Chinese learners of English is a competitive-interference process. Interference is evoked by competition among non-targets, and the interference effect produced by within-category non-targets is more significant than that produced by those from different categories. Among the within category non-targets, those with different semantic relatedness generate different amount of interference effect. As the interference conditions change, the interference effect differs among non-targets from different categories.