This research is initiated as concerns towards the use of grammatically incorrectIndonesian language are increasing. Generally, this study aims to describe language errors in descriptive text essays written by the students in classes VII C and VII E at SMP Negeri 2 Jatisrono. The current research utilizes a qualitative approach with descriptive methods, while the data sources are descriptive text essays. Data collection techniques in this study is Teknik Sadap followed by Teknik Simak Bebas Libat Cakap (SLBC). An equivalent data analysis method with analytical techniques in the form of referential is applied. The references applied are KBBI, PUEBI, and the experts' notion. The percentage of errors identified in the first essay is as follows: spelling 74%, phonology 9%, morphology 9%, syntax 6%, and semantics 2%. The second composition contains some errors with 91% for spelling, 4% for phonology, and 5% for semantics. In the third essay, the percentage of mistakes is 30% for spelling, 16% for phonology, 6% for morphology, 14% for syntax, and 4% for semantics. As for the fourth essay, the percentages of language errors are 84% for spelling, 8% for phonology, and 8% for syntax. In the fifth essay, the percentage of language errors is 30% for spelling, 54% for phonology, 12% for morphology, 2% for syntax, and 2% for semantics.