This research title is “The Differences of Self-Confidence in Speaking Between Students Joining and Not Joining EDSA At Universitas Ahmad Dahlan”. This study conducted to describe the differences of self-confidence in speaking between students who join and who do not join EDSA. This research uses descriptive research. The method of this research is qualitative and quantitative methods. The population of this research are English department students in the fourth semester that joining at speaking class, they are consisting of 46 students totally. The sample of this research used non-random sampling, the researcher used 15 students who join EDSA and 15 students who do not join EDSA, 30 students totally. In collecting data, the researcher uses observation, interview and questionnaires technique. The researcher did observation with several techniques, the first is joining the class, taking a photo in the class and then giving a checklist on the observation paper based on the situation in the class. The researcher recorded the interview data. In the questionnaires, the researcher makes twenty-two items statement and used Likert scale. The result of this research shows that the level of self-confidence in speaking of students who do not join EDSA is classified into fair category. The level of self-confidence in speaking of students who join EDSA is classified into very good category. The result of T-test in inferential analysis there is significant differences of self-confidence in speaking between students joining and not joining EDSA at Universitas Ahmad Dahlan, because t value is 8.816 > 0.05. The description of the difference of self-confidence in speaking between students who join EDSA and students who do not join EDSA can be seen from interview and observation conducted by researcher. Self-confidence in speaking of the students who join EDSA have higher score than the students who do not join EDSA. Keywords: Self-Confidence, Speaking, Self-Confidence in Speaking, EDSA