ABSTRACT Error analysis is a way of investigating errors in the learning of a second or foreign language. It is also the process of observing, analyzing, and categorizing the differences between standard language and language use. This research was aimed at finding out: the types of error of plural nouns on students’ sentences made by the seventh graders of SMPN 14 Palembang. This study used descriptive quantitative research. The data were collected from four classes of seventh grade students with a total of 129 students in SMPN 14 Palembang by using cluster random sampling. This study focused on analyzing the students’ errors in plural nouns, thus some procedures of error analysis was applied, they were: collection, identification, and classification. The frequencies of errors were calculated in percentage. Based on the result of the analysis, there were 2.057 errors found in students’ answers. Furthermore, it was found that the students made 237 (11.52%) errors in omission, 506 (24.60%) errors in addition, 1314 (63.88%) errors in misformation as the highest one. Keywords: Error Analysis, Plural Nouns