本研究对比了两代(2005 / 2023)英语专业学生词汇联想网络的语义组织及整体网络变化。结果显示：1)两代学习者英语心理词库均以语义组织为主，高低水平者对词汇搭配和层级知识的侧重不同，现阶段学生的屈折派生知识显著提高；2)两代学习者的联想网络结构均符合“小世界”特性，网络疏密度随语言水平而增大至稳定，稳定性随小世界程度的加深而减弱。本研究为英语词汇学习提供了历时发展图景，对词汇学习诊断有启示。

This study adopts word association tests to investigate diachronic changes in organizational patterns and network structures of Chinese EFL learners’ word association networks during two decades. Results show that: 1)Chinese EFL learners’ word association networks are dominated by semantic relations, with low and high proficiency participants exhibiting different developmental trends in terms of collocational and hierarchical knowledge; learners in current stage perform a dramatic increase of morphological relations in non-semantic responses; 2)Chinese EFL learners’ word association networks possess the “small-world” property, with sparsity increasing as L2 proficiency grows and stability declining as “small-worldness” increases. This study provides a diachronic depiction of vocabulary learning and insights for vocabulary assessment.