本研究旨在調查高一學生英文字彙學習困難，目的在於探尋高一學生所遭遇字彙學習困難的原因、瞭解課堂上老師所用的字彙敎學技巧、找出課堂上老師所使用的字彙練習活動、檢視用於測驗高一學生的字彙測驗類型、並發掘高一學生所使用的字彙學習策略。 本研究調查對象為臺北區七所公立高中的560位高一學生及三位英文任課教師，研究工具包括學生的字彙學習問卷調查及老師的口頭訪問。 研究結果，發現高一學生英文字彙學習困難的兩項主要原因：(1)高一字彙量太多。 (2)高一相關字彙練習活動困難。此外，最常用的字彙敎學技巧乃是以老師為中心的字彙敎學方法；字彙練習活動如造句及同義字、反義字練習最常用於課堂上；最常用的字彙測驗類型亦是傳統無上下文單題式字彙測驗類型；學生並不常運用字彙學習策略來幫助其學習字彙。除上述研究發現外，並對本研究的侷限及未來從事相關研究給予建議。 / This study investigated Senior I (first-year) high school students’ vocabulary learning difficulties. The purpose of the study was to (a) seek for reasons to account for vocabulary learning difficulties encountered by Senior I students, (b) investigate the vocabulary teaching techniques used in class, (c) find out the vocabulary practice activities used in class, (d) examine the vocabulary assessments given to Senior I students in class, and finally (e) explore vocabulary learning strategies used by Senior I students. 560 Senior I students and three teachers from the seven senior high schools in Taipei area participated in the present study. A vocabulary learning questionnaire was administered to the students, and the three teachers joined the oral interviews. Data were collected through the questionnaires for the students and oral interviews for the three teachers. Descriptive statistics were computed for data analysis. Two major reasons that account for vocabulary learning difficulties encountered by the Senior I students were: (1) huge increase of vocabulary size in Senior I and (2) more demanding vocabulary practices in Senior I. Besides, the most popular vocabulary teaching techniques were conventional teacher-centered ways of presenting new vocabulary items. Vocabulary practices such as sentence making are frequently used in senior I class, followed by synonym and antonym practices. Traditional decontextualized vocabulary assessments were frequently used in class. Finally, the students did not utilize vocabulary learning strategies frequently to help their vocabulary learning. Along with these findings, limitations of the study and implications for future research have been suggested.