Mother tongue plays a significant role in language learning. The issue of whether and how to use mother tongue as a medium of instruction to increase foreign language learning and teaching efficiency is especially important. Thus, a pilot study aiming at exploring teachers’ and students’ perception of mother tongue use in foreign language teachers of English, French, German, Spanish and Japanese departments as well as English majored students at Wenzao Ursuline College of Language. They were asked to answer a researcher-constructed questionnaire concerning beliefs and opinions of mother tongue use in foreign language classrooms. One major result indicates that while a great majority agreed with the maximum use of the target language, they had reservation with its exclusive use. Accordingly, most of them thought that mother tongue is needed for some pedagogical purposes and that mother tongue use is beneficial to students’ affective development. Furthermore, teachers’ foreign language department and students; year group are factors in determining a significantly different perception of mother tongue use. In addition, pedagogical implications yielded from the results of this study are discussed, classroom techniques as to how and when to use MT are offered, and directions for further studies are suggested toward the end of this paper.