Source-based writing research has received much attention in recent years, which generally shows that both novice and expert EFL (English as a foreign language) writers have difficulties in writing from sources. As many Chinese institutes of higher education attach increasingly more importance to publications in international journals, citation and plagiarism become critical issues for both student and teacher researchers as well as the institutes. Nevertheless, not much research can be found on the issues with Chinese students, especially undergraduate students. The present study thus investigated Chinese undergraduate EFL learners' perceptions of plagiarism and use of citations in their course papers. A total of 141 students from a highly prestigious university answered an open-ended questionnaire and 97 of them submitted course papers. Major findings were: (1) the students had a (fairly) good knowledge of plagiarism and identified various reasons for plagiarism in academic writing, (2) they used summary the most often when citing from sources, followed by paraphrase and quotation, and (3) they mainly used single-source citations to primarily support their own ideas, position an author's opinions and/or findings, and acknowledge the author's ideas. These findings reveal a general overview of students' perceptions of plagiarism and use of citations in their course papers, thus providing implications for formal classroom instruction of writing from sources.