本研究主要目的為以縱貫性的觀點分析臺灣的大學生的學業自我概念與其英語能力之間的相關。樣本為101位被編入不同能力等級修習英文課程的EFL大一新生。他們除了於學年初及學年末接受學業自我概念量表的測驗之外，並且完成中級GEPT聽力與閱讀測驗。積差相關與迴歸分析的使用是在探究下列研究問題：(1)學業自我概念與英語能力是否於學年前後都存在著顯著的相關？(2)學生先前的學業自我概念是否能有效地預測他們日後的英語表現？(3)學生先前的英語能力是否能有效地預測他們日後的學業自我概念？研究結果顯示EFL學生的學業自我概念與其英語能力之間有著顯著的相關，這兩變數於學年前後都屬中度相關（分別是.516和.429）。此外，學年初所測得的學業自我概念可作為學生日後英語表現的顯著預測變項，同樣的，學生先前的英語表現亦對日後的學業自我概念具有顯著的預測力。學業自我概念的兩個主要構成要素中，學業上的努力比學業自信心對於預測學生日復英語表現有更顯著的貢獻，而對於學生日後學業自我概念的預測，聽力能力是比閲讀能力更好的預測變項。研究結果證實學業自我概念與英語能力之間的關係是相互影響的。

This study intends to examine the relationship between student perceptions of academic self and English proficiency among university students in Taiwan from a longitudinal perspective. The subjects included 101 EFL freshmen assigned to different ability level classes for English instruction. They were not only assessed for their academic self-concept but also administered intermediate level GEPT listening and reading tests twice, at the start and end of their first academic year. Correlational and multiple regression analyses were conducted to ascertain (1) whether academic self-concept is significantly related to English proficiency both at the beginning and the end of the academic year, (2) whether students' prior academic self-concept scores can significantly predict their subsequent English performance assessed after a period of one academic year, and (3) whether students' prior English proficiency scores are able to significantly predict their subsequent academic self-concept near the end of the school year. The findings reveal that these EFL students' academic self-concept and their language proficiency are significantly correlated. Moderate Pearson correlations between these two variables were obtained both at the beginning and end of the academic year (.516 and .429 respectively). Further, students' prior academic self-concept measured at the beginning of the first semester served as a significant predictor of subsequent English performance. Likewise, prior English performance significantly contributed to the prediction of subsequent academic self-concept. Of the two major factors of academic self-concept, academic effort contributed more to the prediction of subsequent language performance than academic confidence. Student listening proficiency served as a better predictor of subsequent academic self-concept than reading proficiency. The findings establish a mutual relationship between the students' domain-specific academic self-concept and their language proficiency.