This study aimed at understanding the knowledge business performance of service quality within an Foodservice industry have with the word-of-mouth. And we also looked into how such a knowledge business performance changes depending on the leadership of the supervisors and the efforts for self-development by the members of the service quality. The data was collected from 440 people in hotel and then analyzed by using SPSS/WIN 15.0 software package. Upon putting the questionnaires into a coding process, we conducted frequency analysis, Scheffe’'s method and multiple regression, using the SPSS 15.0 for Windows system.