With the development of mobile Internet technology and the rapid advancement of information globalization, China has entered the era of "mediated society". To realize the positive function of media for Adolescents, it is indispensable for Adolescents to have correct knowledge of media information, reasonable use of media, and qualified media literacy ability. At the same time, based on the high participation of Adolescents in social media, online socialization has put forward higher requirements for Adolescents media literacy. In this process, media literacy becomes a guide for teenage Internet users' behavior.
Body Image is one of the important issues facing adolescents' healthy growth. The use of social media has become an indispensable part of adolescents' daily life, and some studies have shown that selfie behavior on social media is considered to be an influencing factor on adolescents' body Image, and it is important to sort out its mechanism of action to form good body Image and healthy physical and mental development.
Existing researches have conducted cross-sectional studies and longitudinal tracking studies to explore the influence of social media on adolescents' body Image in terms of social media use time and frequency (Wei Qi et al., 2017; Holland & Tiggemann, 2016), and related studies have found that, compared with simple measures of social media site use time and frequency, specific activities on social media sites ( specific activities) (e.g., posting status, viewing, commenting on friends' status, etc.) have a more significant predictive effect on body Image dysregulation than simple measures of time and frequency of social networking site use. Not only has there been no uniform conclusion on the specific mechanisms of social media effects on adolescents' body Image, but there are also few studies on the effects of selfie behavior. It is believed that the role of social media selfies as an emerging social interaction mode on adolescents' body Image needs to be further investigated.
Therefore, this study aims to investigate the mechanism of social media selfies on body Image, and to explore whether media literacy plays a mediating role. Based on the high penetration rate of the Internet in first-tier cities in China and the more significant characteristics of the younger age of Internet access, the study adopted the purposive sampling method and questionnaire survey method, and selected junior and senior high school students in first-tier cities as the sample, and asked the participants to fill in the questionnaire materials, which included the media literacy scale and the social media selfie involvement scale. The main statistical methods used were: correlation analysis, regression analysis, t-test, and one-way ANOVA.
This study will enrich the research related to adolescents' body imagery and social media selfie behavior in the context of digital life in China, reminding us that the issue of cultivating adolescents' body imagery can be focused on the level of media literacy of adolescents and scientifically enhancing the ability to use media in the digital era. This is important for guiding adolescents to use smart technology correctly in their daily lives and to participate reasonably in the Internet society.