The study investigated variation in the depth of vocabulary knowledge of L2 learners at the same vocabulary breadth and the learner-related factors affecting it. Two hundred and thirty-one EFL learners at high and low levels of vocabulary breadth (according to Vocabulary Level Tests) participated in the study. The study tested Vocabulary depth (Word Associates Test and Derivative Word Form Test) and learner-related factors (LLAMA Aptitude Test, Attitude/Motivation Test Battery, Vocabulary Learning Strategies Survey, and Learning Style Inventory). Based on the findings using a paired t-test and Pearson correlations in SPSS and Structural Equation Modelling in AMOS, the study confirmed that (1) learners at the same level of vocabulary breadth (particularly low level) possessed variation in the depth of their vocabulary knowledge (such as meaning-based vs. form-based and receptive vs. productive knowledge) and (2) among the learner-related factors, learners’ language aptitude and motivation had a significant impact on vocabulary depth. Based on the results, the study made some pedagogical suggestions.

该研究调查了相同词汇广度下第二语言学习者词汇知识深度的变化以及影响其的学习者相关因素。词汇广度水平高低（根据词汇水平测试）的 231 名英语学习者参与了这项研究。该研究测试了词汇深度（单词关联测试和派生词形测试）和学习者相关因素（LLAMA 能力倾向测试、态度/动机测试电池、词汇学习策略调查和学习风格清单）。基于 SPSS 中的配对t检验和 Pearson 相关性以及 AMOS 中的结构方程模型的结果，该研究证实：(1) 处于相同词汇广度水平（特别是低水平）的学习者的词汇深度存在差异(2)在学习者相关因素中，学习者的语言能力和动机对词汇深度有显着影响。根据研究结果，本研究提出了一些教学建议。