在语言磨蚀 30 多年的研究历程中，雅柯布逊回归假设的验证一直是该领域的研究热点之一。然而， 通过实证研究验证且符合雅柯布逊回归假设预期的目标成分，均局限于词法和句法， 并不包含词汇。为此， 本文针对 116 名中国大学毕业生，采用接受性词汇测量方法， 分析了外语词汇学习和磨蚀的动态过程， 从理论上阐释了动态过程的特点。所得基本结论如下: ( 1) 外语词汇与词法和句法等一样，在磨蚀过程中均表现出明显的回归性，符合雅柯布逊回归假设的预期; ( 2) 外语词汇磨蚀的回归性表现为“先学习的外语词汇， 后磨蚀” ; ( 3) 以“BIA-d 模型” 为核心的“外语词汇学习与磨蚀的理论模型” ，既可用于外语词汇学习过程的分析，也可用于磨蚀回归性的阐释。

Testing Jakobson's Ｒegression Hypothesis has been one of the hot issues in the field of language attrition since language attrition was researched thirty years ago． However， the target items tested and validated have been at either morphological level or syntactic level， none at lexical level． This paper， trespassing the boundary， set out to look into the process of the foreign lexical learning and attrition among 116 Chinese college graduates by measuring their English receptive vocabulary， and this dynamic process was found to be working within a model． Specific conclusions are: ( 1) foreign lexis regresses with time in attrition just as morphological and syntactic items do， which is expected by Jakobson's Ｒegression Hypothesis; ( 2) the regression of foreign lexis in attrition can be described as“first learned， last out” ; and ( 3) the Theoretical Model for Foreign Lexical Learning and Attrition， adapted mainly from BIA-d Model， is able to illustrate both the process of foreign lexical learning and the regression of foreign lexical attrition．