ABSTRACT This study explores the effects of using social networking on college students’ English writing skills and confidence in the process of cooperative learning. This study use both qualitative and quantitative research. The qualitative research includes peer feedback, group interviews and classroom observations. The quantitative research includes the scores from peers and questionnaires. The writing activities conducted in this study are used to determine if the sixty college students from Asia University improved their writing skills and increased their confidence with the scores and the peer feedback given under cooperative learning.The results of this study show that the greater the amount of feedback the students received on specific aspects of English writing skills, the more the students improved on specific aspects. It was found that peer feedback ameliorated college students’ English writing skills, especially with their writing activities, content, and attitude; and increased their confidence in writing English. In addition, most of the college students kept an authentic and objective attitude toward giving feedback. Nevertheless, few students gave subjective feedback depending on personal preferences. Furthermore, not only the feedback-receivers improved their writing skills, but also the feedback-givers gained by reflecting on their own learning while giving feedback. Cooperative learning created an exquisite learning atmosphere in the classroom. This study suggests that teachers could conduct writing activities in class through cooperative learning so as to provide students more opportunities to practice English writing in class and encourage students to give more peer feedback.Key words: writing activities, Facebook, social networking, English writing skills