Abstract
This study aims to determine students’ pronunciation errors in pronouncing consonant sounds in speaking performance. This research is descriptive quantitative with 352 population. The sample of this study was 64 students who were selected by using cluster random sampling technique. The data were collected through pronunciation test, a questionnaire, and interview. The pronunciation test and the questionnaire were analyzed by using formula of the percentage, while the interview recordings were transcribed. There are two findings of percentage in consonant sounds in speaking performance. (1) There are 6 kinds in consonant sounds made by students' speaking performance, namely Alveolar (38.18%), Interdental (34.65%), Alveo-palatal (12.20%), Labiodental (11.81%), Velar (1.79%), and Bilabial (1.38%); (2) Factors that cause students made pronunciation errors in speaking performance are generally influenced by their mother tongue (81.25%), less using English in their daily life (66.67%), unchallenging lessons (56.25%), being passive learners (59.37%), less of confidence while performing (62.50%). Therefore, it can be concluded that there are 6 kinds of consonant errors in students' speaking performance and many errors in pronouncing alveolar sounds. As the results, the students needed to have more exercises in pronouncing the consonant sounds in speaking in order to make it easy to be understood and avoid misunderstandings.