The purpose of this paper is to evaluate impacts of social media marketing on the image of Samsung's brand in the Vietnam market. Data were collected online from 200 customers through social media sites. Descriptive statistics, Cronbach Alpha and Regression have been used in this study. Social media marketing activities that focus on entertainment, interaction, trendiness, and promotion have been shown to have significantly positive effects on the brand image. It is advised enterprises to pay more attention to the value of Interaction and Promotion on social media sites.