This research was aimed to find out the types of grammatical errors made by EFL senior high school students in writing an analytical exposition text, the causes of their grammatical errors in writing the text, and their attitude towards errors correction suggested by their teacher. This study was done based on the realisation that the grammatical errors are considered the most common errors found in students’ analytical exposition text and the role of the teacher’s errors correction in writing. This study applied descriptive qualitative research design. The data were taken from the students’ writing product purposively and a semi-structured interview with 10 guided questions. The researcher identified and described the errors based on the steps of Dulay, Burt, Krashen (1982), whereupon the researcher calculated the total number and percentage of each kind of errors and found the causes of the students to make the errors. Through document analysis of 10 students’ texts, the present study found the highest frequency of students’ grammatical errors was omission which consisted of 53.40%, the second was misformation which consisted of 38.63%, and then the third was addition which consisted of 5 errors or 5.68%, and the last was misordering which consisted of 2.27%. Besides, the findings in the interview session suggest that the students considerd the teacher’s errors correction influenced their recognition in writing. However, the teacher’s written corrective feedback should be combined with oral feedback to help the students have better understanding towards the feedback given by teacher. Keywords: Grammatical Errors, The Causes of Errors, Analytical Exposition Text, and Students’ Attitude.