This study examines impact of the educational use of Facebook group on the high school students' proper usage of language. The study included thirty students who attend 11th grade in a high school in Trabzon, Turkey. Firstly, preliminary data about Facebook usage of students were obtained to understand the factors that motivate students to use Facebook and whether they use them for the educational purpose or not. Then, a Facebook group was created, in which a literature teacher was assigned as the guide of the group. This study lasted twelve weeks. The students' assignments such as compositions, poems, and vignettes, discussions, the teacher's views and observation, data from the interviews with participants were analyzed in this study. Results from this study indicated that that Facebook group was effective on issues such as development of writing abilities of students, communication and cooperation between teacher and students, and cooperation and communication among students. The original idea for this research was to determine that proper usage of language can be improved in social context if Facebook group is created as a flexible online community with interactive and reflective activities, effective tool of sharing and communication. This study demonstrates how Facebook can successfully be used in educational environment appropriately.