20世纪前半叶，现代汉语白话文的句子结构发生了重要变化，显著表现之一是定语长度增长与容量扩 增。本文借助历时复合语料库（ 1915—1949），以“一个＋修饰语＋的＋名词”为例，首先描述这一结构在翻译汉语与原 创汉语中的频率、变化趋势，接着从语言接触和认知视角分析该结构变化的可能性与限度。研究发现：相对旧白话，“五四运动”后短时间内现代汉语白话文的定语长度增加、容量扩展。除了语言自身发展外，以翻译为媒介的语言接触推动了这一进程；由于汉语自身对结构容量扩增十分敏感，再加上认知处理能力的限制，这种扩展有一定限度。

In the first half of the 20th century, the sentence structure of modern Chinese saw great changes, one of which related to the lengthening and expanding of modifiers. By focusing on the attribute modifiers in the structure of “a / an / one + modifier +de + head noun” over time in translated Chinese and non-translated Chinese based on diachronic multiple corpora covering the period 1915 -1949, the present study details the frequency and changes, analyzes their causes, and summarizes the features from the perspectives of language contact and cognition. The findings show that the length and capacity load of the attribute modifier were expanded shortly after the May Fourth Movement, a special period during which a flurry of translation activities are thought to have shouldered the mission of reforming Chinese and adopting new ideas from the West. Besides the development of modern Chinese itself, translation induced language contact may have propelled the process. However, modern Chinese is greatly sensitive to the lengthening and expansion, for long attribute modifiers are needed more cognitive efforts, therefore, the expansion is limited.