Mobile instant messaging (mobile IM) is a cutting edge technology of the P2P communication. The prevalence of the mobile IM boosts the research of the perceived satisfaction and loyalty towards mobile IM long-term usage. In the era of 4G, individuals use mobile IM to communicate with their friends in every-day life. However, prior studies neglected a holistic view of users' roles and then yielded insufficient explanation about the usage satisfaction of mobile IM. Based on the integrated users' role framework, this research-in-progress explores the determinants of mobile IM satisfaction and loyalty with the consideration of the triangulation perspective of users' multiple roles: the technology user role, the service consumer role, and the network member role. To this end, a survey is designed to collect data from mobile IM users. The data analysis results will validate the proposed hypotheses.