The study focuses on the relationship among service quality, customer satisfaction, and customer loyalty. The SEM approach was used to investigate the causal relationships between the above constructs and identified the fitness of the model. The study selected six hundred customers in Taiwan area as its samples, and adopted the linear structure relationship (LISREL) as a statistic method. The results of this study are summarized as follows: (1) Service quality has significant positive influence on customer satisfaction. (2) Customer satisfaction has significant positive influence on customer loyalty. (3) Service quality has an indirect effect on customer loyalty through customer satisfaction. In conclusion, the telecommunication industry ought to maintain its customer loyalty by improving its customer satisfaction and service quality.