Social networks and communication on theInternet have an important role in people's daily lifeworldwide. This paper examines the impact of Socialnetwork usage on the Academic performance of students. The research data were collected from a stratified sampling survey including 576 Vietnamese undergraduate students. The research model has five independent variables (Perceived usefulness, Perceived ease of use, Social influences, Facilitating conditions, Community identity), one mediating variable (Social network usage), and onedependent variable (Academic performance). The studymethods include the Cronbach’s alpha test, the Exploratory factor analysis, the Confirmatory factor analysis, and the Structural equation modeling are employed toquantitatively analyze the relationship among variables.The result finds that there are positive and significantimpacts of Perceived usefulness, Perceived ease of use,Social influences, Community identity on Social networkusage. The impact of Facilitating conditions on Socialnetwork usage is positive, however, it is not significant.The result also concludes that there is a positive andsignificant impact of Social network usage on theAcademic performance of students. Besides, the empiricalstatistical data indicates that social networks are really apopular and familiar tool for helping students tocommunicate with each other in Vietnam. Finally, thestudy result suggests that educational managers may usesocial networks as an informal tool to enhance not only the academic performance of students but also othereducational activities in universities.