This research was conducted to describe the kinds of grammatical errors, to discover the sources of the errors, and to find out the strategies in grammatical errors. This study applied descriptive qualitaive research design. The subject was the second-semester students of the English Department of Teacher Training and Education Faculty of University of Islam Malang. The researcher observed the 28 students’ descriptive text from one class who were chosen using purposive sampling. The instrument used was students’ descriptive text to get the data and also use the questionnaires by Pawlak (2018). Based on the analysis, the data showed that the total grammatical errors made by the students were 76 items where the errors of omission were 33 items or 43.4%, errors of addition were 21 items or 27.6%, errors of misformation were 15 items or 19.7%, and error of misordering was 7 item or 9.2%. Moreover, the grammatical errors made by the students were caused by intralingual errors with 69 items, and interlingual errors with 7 items. Therefore, the grammatical errors mostly produced by the students were errors of omission which were mostly caused by their lack of knowledge of target language. The researcher could say that the students were lack of grammar mastery, so it made them applying their own rules for expressing their idea. Moreover, most of the students used incorrect grammar rules in their sentences. In general, those errors were mostly caused by intralingual errors. Although this study was conducted at the university students level, this study proved that there were many university students confused in using the correct grammar in their text. Based on the data, it could be seen that metacognitive and cognitive strategies are the most grammatical strategies that used by the students, then social strategies become the next strategies mostly choosen by the students and the strategies that have the lowest respons from the students are affective strategies. To sum up, the student’s understandings of the use of English structure were still low. The suggestions for the next researchers are to work more on the solutions of the sources of the errors made by the students, the future researcher also can analyze the other object besides students’ text, for example on the students’ video project focusing on speaking aspects. Further researchers can also examine the effect of strategy implementation on grammatical errors by using an experimental design. Key Words: Error Analysis, Types Of Grammatical Errors, Sources Of Errors, Descriptive Text, and Grammar Learning Strategies