Abstract: The advent of social media has altered the traditional way of interpersonal interaction and diversified both the methods and strategies for people to present themselves. Social media avatar plays a crucial role in the formation of a user's social image. The choice of avatar varies greatly from person to person. With the aim to analyse the relationship between the motivations of using social media and the choice of an avatar, this paper surveyed the current usage of WeChat avatar among college students, the motivations behind each choice and their relationships, by using a questionnaire. This study indicates that college students are not willing to reveal too much personal information in the WeChat avatar. A preference of post-production for their photos is present in avatar presentation. In addition, the motivations for entertainment, expanding social network and peer conformity have a notable impact on their avatar decision.