An Analysis of Students' Pronunciation of Words Suffix – ed of The Seventh Semester Students At English Study Program of The University of Sisingamangaraja XII Tapanuli In Academic Year 2017/2018. This study investigated the pronunciation capability of the seventh semester students of the English study program University of Sisingamangaraja XII Tapanuli in pronouncing words suffixing –ed. The sample of this study was the whole students of semester seven, and there were fifteen of them. They were chose as the sample with the assumption that they have passed all the subjects proposed or given. In this study, the researcher applied qualitative research method. The instrument to get the data was by giving test. The test referring to pronounce words suffixing – ed, in which there were six classification of it, and each of them consisted of items (words suffixing – ed with the last sound; voiced, voiceless, d, t, vowels, and unique sounds). The data was analyze by calculating the number of correct and incorrect pronunciation made by the students, then positioning them based on the grade they got. Based on the analysis, it was found that there was no student who got A (excellent) grade (0%), there were two students who got B (good) grade (13.3%), there were two students who got C (average) (13.3%), there were four students who got D (poor) grade (26.6%), and there were seven students who got E (fail) grade (46.6%). It concluded that the seventh semester students' pronunciation of English study program in academic year 2017/2018 was under poor, in other words most of them failed the test. There could be some sources why this problem occurred; the wrong imitation made by the students from their educators, lack of practice, and the unsuitable technique. For that the writer suggested that being an educator, we have to be careful for we are being imitated, it is good to use sounding dictionary, native speaker in teaching and learning process, and the students must improve both their listening and pronunciation since they are unseparated by English songs, movies or videos as they now abundantly available on internet.