With the development of Internet and mobile devices, social network services (SNS) have become an indispensable part of people's daily lives, and with the popularity of SNS, users have also changed their ways of communication. However, online text communication between people lacks nonverbal cues, which often leads to misunderstandings or ambiguity. Emoji, a common language in the digital age, is often used not only in communication between different social network systems, operating systems and languages, but also by the users of SNS as the first choice for non-speech communication. This study used the technology acceptance model (TAM) and the unified theory of acceptance and use of technology (UTAUT) to find out and verify the factors affecting the use of emoji in social service networks. In this study, 422, 153 and 158 valid samples were collected from Taiwan, Japan and Korea, respectively, and were analyzed by AMOS 21 and PLS (partial least squares). The results showed that the perceived usefulness, perceived ease of use, subjective norms, perceived playfulness and fashion involvement of the Taiwanese samples had a positive impact on usage intention. For the Japanese samples, only perceived usefulness, subjective norms and perceived playfulness had positive effects on usage intention; for the Korean samples, only subjective norms and perceived playfulness had a positive effect on usage intention.