Keywords: Writing, Mind Mapping, Descriptive Text This study aims to find out whether the implementation of Mind Mapping improves students’ writing skill of junior high school or not. Therefore, this study uses quantitative research in carrying out the research. This study only focus on improving students’ ability in writing descriptive text in all writing aspect which are content, organization, vocabulary, grammar, and mechanics. The population of this study is first grade students at SMPN 7 Banda Aceh, while the sample of this study is VII-7 class which consists of 27 students. The result of this study shows that students’ score increases, proven by their scores of pretest and posttest. The mean score of pretest is 8.41, and the mean score of posttest is 11.52. Moreover, the result of hypothesis testing indicates that alternative hypothesis (Ha) is accepted and null hypothesis (Ho) is rejected. It is shown from the calculation of T-test, 7.37, which is higher than T-table. Hence, Mind Mapping can improve students’ writing skill better in all aspects. Therefore, the writer concludes that teaching writing by using Mind Mapping gives good effect for students’ ability in writing aspects.