摘要:AbstractThis study focuses on determining the effects of portfolio on learning products on eighth grade students in foreign language learning. The pre test-post test experimental design with a control group has been used in the research. Two groups were randomly formed as an experiment and control group in this experimental study which lasted twelve weeks. The teacher handbook activities were used with the control group. But in the experiment group, portfolio activities were also used. At the beginning and at the end of the study, both groups were given an achievement test and a scale to measure attitudes towards English. Thus, the effects of portfolio on success and attitudes towards English were investigated. An achievement test which consisted of 20 multiple choice questions concerning grammar and vocabulary, listening test with 15 questions, reading test with 15 questions, speaking test with 15 questions and writing test with 15 points were developed. The attitude scale towards English consisted of 34 items. Also, students in the experiment group were given five open-ended questions to find out what they thought about portfolio. At the end of the research, it revealed that portfolio had positive effects on students’ achievement, but it had no effect on attitudes towards English. Additionally, it had positive effects on writing, listening and reading skills but no effect on speaking skills. The analysis of the open-ended questions revealed that students liked the portfolio application and they had positive attitudes towards learning English in general. On the other hand, the interview with the students made it clear that students like portfolio activities.