As the dependence on 3G grows tremendously, it undoubtedly fosters the birth of 4G. Acknowledging the enormous profit brought by the 4G, telecoms in Taiwan all exert their full strength in order to attract more customers to adopt or advance to 4G services. Hence, this study exemplifies users of 3G or 4G and aims to explore the relationships among brand image, perceived value, customer satisfaction and customer loyalty. The data are collected from questionnaires and apply statistical techniques including descriptive statistical analysis, factor analysis, reliability analysis, and structural equation modeling to examine 3G or 4G users’ experiences. The results are as the following. First, brand image has positive influence on perceived value and customer loyalty. Second, perceived value can enhance customer loyalty. Furthermore, customer satisfaction helps promote customer loyalty.