Since social presence theory was introduced, many researchers have tried to apply it to various technology-mediated communication media, including E-Mail, videoconferencing, and instant messengers. Yet few researches have investigated the influence of mobile video-mediated communication (VMC) on the social presence despite prevalence in business practices. In this paper, a research model is developed to test the relationship between the mobile VMC (video telephony and video chatting) and the level of social presence. And the task equivocality, whether it's an intellective task or a negotiation task, is also considered as moderating variables, based on the task-media fit proposition. Hence, mobile video chatting could be suggested as an alternative media of mobile video telephony for less equivocal informative tasks according to this study.