對許多語言學習者而言,寫作一直是最複雜的語言技能之一。為了幫助學生發展這項技能,許多研究一直致力於探討影響學生作家的潛在因素,例如,事前寫作任務(pre-planning tasks)對學生寫作表現的影響。然而,在眾多研究因素中,時間因素對學生寫作表現的影響卻很少被探討,這樣的欠缺在以英語為外國語(English as a foreign language: EFL)的台灣教育情境下更是顯著,尤其是時間因素對寫作複雜度的深度探討更是匱虞。為了釐清這個研究缺口,本論文以時間做為影響因素,探討42位台灣EFL學生的寫作複雜度表現。受試者必須分別完成兩組時限內的寫作考試:(一)20分鐘對比40分鐘,以及(二)30分鐘對比50分鐘。本研究一共收集168篇寫作樣本,並以推論和敘述性統計進行資料分析。結果顯示,時間在台灣EFL學生的寫作複雜度上的確扮演重要角色。準確地說,台灣EFL學生在較多的時間資源下比較少的時間資源下能夠在寫作上表現出更高的複雜度;換句話說,在時間壓力受限的狀況下,學生將無法充分將語言複雜度展現於寫作之中。本研究最後將以討論進行結論,同時提供未來學者進一步的研究方向。 Writing has long been considered to be one of the most complex language skills for language learners to master. To help students develop this skill, many studies have been devoted to exploring potential factors affecting student writers’ performance, such as the effect of pre-planning tasks. Among the many other factors examined, however, the sheer effect of time on students’ writing performance is rarely studied. This is particularly true in the educational context of Taiwan, where English is mostly learned as a foreign language (EFL). The understanding of Taiwanese EFL students’ linguistic performance in terms of writing complexity is especially limited. To shed light on this research gap, this thesis explores the effects of time factors on a group of 42 Taiwanese EFL students’ writing complexity. The participants involved were required to complete two sets of timed writing tests: (1) 20 minutes versus 40 minutes, and (2) 30 minutes versus 50 minutes. In total, they produced 168 writing samples for analysis, for which both inferential and descriptive statistics were employed. The thesis results show that time factors play an important role in Taiwanese EFL students’ writing complexity. Specifically, with greater time resources, Taiwanese EFL students write with more complexity than those with less time resources. This thesis concludes by providing discussions and identifying possible reasons for further studies.