Due to the widespread use of smart phones with enhanced functions, telecom service providers Have responded in a variety of contexts but have yet to attract enough customers as expected. Few studies have been conducted to understand antecedents for using smart phone mobile services in Taiwan. To acquire a better understanding of why people use smart phone mobile services, we used focus groups to investigate the smart phone consumption decision process. This study combined existing theories, Unified Theory of Acceptance and Use of Technology (UTAUT), perceived playfulness, with new factors discovered through focus groups, to develop a three-stage model for smart phone use antecedents. This model can be adopted by related operators and companies as a foundation for setting business strategies and marketing programs, and also as a reference for other researchers to examine the relationships in the model.