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.