成人學習者的口說焦慮程度和擔憂被他人評斷會影響他們的口說表現的這個議題越來越被處在EFL領域的研究者所關注。然而討論學習者的口說焦慮和同儕壓力之間關聯性的研究尚為不足。因此，本研究的目的在於探討同儕壓力影響口說焦慮的程度。本篇的研究方法為包含了口說焦慮和同儕壓力量表的一份問卷。在分析所蒐集到的資料後，將受測者依據口說焦慮程度高、中、低來挑選出六位，進而進行一對一的半結構式訪談。研究結果顯示受測者的口說焦慮程度和本身的個性及過去學英文的經驗有關。同時，受測者的同儕壓力程度會因彼此的熟識度提升而降低。此外，學生在低壓力的英語學習環境下也比較願意說英文。總結而言，研究者建議英語教師能夠先從降低學生的口說焦慮著手，進而讓同儕壓力對英文口說的影響程度降至最低。 Researchers of the EFL field had increasingly paid attention to the adult learners’ speaking anxiety and the fears of being judged by others would affect their oral performance. However, research which had empirically documented the link between learners’ speaking anxiety and pressure from peers is lack of adequate discovery. Therefore, the aim of this study was to explore to what extent peer pressure affects speaking anxiety. This research used a questionnaire, whose questions included speaking anxiety and peer pressure scales. After analyzing the data collected from the questionnaire, six participants who had high, middle, and low level of speaking anxiety were chosen to take part in one-on-one semi-structured interviews. Results of this study showed that participants’ level of speaking anxiety is related to their personalities and previous English learning experience. Meanwhile, the participants’ levels of peer pressure would reduce as familiarity between each other increasingly rising. Moreover, students were more likely to speak out in English under a low pressure environment. To conclude, the researcher suggested that English teachers should first decrease students’ speaking anxiety in order to minimize the degree of influence that peer pressure brings to English speaking performance.