The objectives of this research were to find out the significant difference of students’ writing achievement after using Instagram and to investigate the students’ perception of using Instagram in writing. The research was conducted among the second-grade students of SMA Negeri 14 Bandar Lampung in 2020/2021 academic year. The data were collected by using writing test and questionnaire. The data were collected by using writing tests (pre-test and post-test in the forms of analytical exposition text) and a close-ended questionnaire. The data taken from the test were analyzed by using a Paired Sample T-test and the data collected by using the questionnaire were descriptively analyzed. The result showed that there is a significant difference of students’ writing achievement after the implementation of Instagram. It was also found that students’ perception of the implementation of Instagram was positive.Keywords: Instagram, writing, perception.DOI: https://dx.doi.org/10.23960/UJET.v10.i1.202109