The rapid growth of services provided by the service sector. Many consumers complain about the low quality of services they receive.These companies are not involved in the modern concept of service quality. Based on the circumstances of the field, researchers want to know the quality of the service that affects customer satisfaction. Services provided are guided by service quality dimensions consisting of responsiveness, reliability, assurance, empathy and physical evidence. Increasing competition requires businesses to maximize their quality of service to survive performance in business competition and to create customer satisfaction. The purpose of this study is to determine the quality of service quality on customer loyalty in Mari Rasa Bakery. The type of research used is testing and hypothesis testing quality data using 67 customers from Mari Rasa Bakery. The service quality has an effect on customers loyalty with the result of being able to be seen in a square of 0.976, which means service quality has an effect of 97.6% on customer loyalty and the other 2.4% is the effect from others. From the result of simple linear regression test Y = 0.720 + 0.786 x shows the consistent value of sustainability variable is 0.720 and regression coefficient x of 0.786. The quality of service has a significant effect on customers loyalty. Mari Rasa Bakery management should improve the quality of the Service so that customers Loyalty can always be fulfilled.