Recently, online dating has become increasingly popular for people to look for partners. A new era of online dating has taken place as Tinder, the location-based social dating app, becomes the leader of online dating applications. This thesis explores the user experience of non-heterosexual women and transgender individuals at Tinder, including their motivations for using Tinder, their self-representation at Tinder, as well as the meaning of Tinder to their sexuality expression. In order to get a comprehensive interpretation of sexual minorities on social dating apps like Tinder. Theories such as ephemeral social media, front and back region, impression management, and so on are incorporated in this thesis. Additionally, 10 qualitative semi-structured interviews with CDA (Critical Discourse Analysis) as an analysis tool were performed with non-heterosexual women (progenitors, bisexuals and queers) (n = 8) and transgender individuals (n = 2). Studies show that social media play an important role in sexual minorities and sexuality exploration and expression. However, the outcome of this study shows that Tinder as the leading social dating app is not important for sexual expression for non-heterosexual women, rather, it's a platform for boosting security and increasing social skills. For transgender participants, Tinder is important to expression of sexuality, as it is considered as a way to meet likeminded people. Studies show that social media play an important role in sexual minorities and sexuality exploration and expression. However, the outcome of this study shows that Tinder as the leading social dating app is not important for sexual expression for non-heterosexual women, rather, it's a platform for boosting security and increasing social skills. For transgender participants, Tinder is important to expression of sexuality, as it is considered as a way to meet likeminded people. Studies show that social media play an important role in sexual minorities and sexuality exploration and expression. However, the outcome of this study shows that Tinder as the leading social dating app is not important for sexual expression for non-heterosexual women, rather, It is a platform for increasing security and increasing social skills. For transgender participants, Tinder is important to expression of sexuality, as it is considered as a way to meet likeminded people.