This book aim to explore what are the reasons for college students to prefer in using SNSs in learning English language. This investigation applies self-efficacy theory to explain how using SNSs will affect students’ beliefs. The study used questionnaire to conduct empirical research,collect, and analyze data of 286 participants from Umm AL-Qura University in Makkah in KSA. The findings clearly reflect that there is no significant difference between female and male groups in familiarity with SNSs. There is a significant positive correlation between reasons for using SNSs and students’ academic self-efficacy. Multiple regression analysis showed only non-academic reasons for using social networking sites technology and it has a positive effect on the students’ academic self-efficacy. The results suggest that using SNSs in daily life for non-academic reasons will promote students’ academic self-efficacy for informal learning purposes. As well as using SNSs in academic field with regulated learning environment may promote both effective methods of teaching and learning English language.