This study based on theory of planned behavior from Ajzen (2002) and the concepts of organizational citizenship behavior from Lin (1992), the purpose of this study intended to explore the knowledge sharing behavior of food & beverage industry operation staffs The objectives of the study were to investigate the interrelationships among individual's attitude, subjective norm, perceived behavioral control, and behavior intention. Furthermore to examine the relationships among knowledge sharing behavior with internalization, externalization, socialization and combination factors form Nonaka & Takeuchi (1997), behavior intention, and organizational citizenship behavior. There were 273 employees of food & beverage industry in Taiwan being investigated by quota sampling and survey data were analyzed by using descriptive statistics, independent sampled t-test, one-way ANOVA, and linear structural relationships (LISREL). The findings of the study indicated that: 1. There were significant differences between levels of employees' background characteristic and some of variables in knowledge sharing behavior model. 2. Employees' attitude and perceived behavioral control were positively related to behavior intention, but there weren't significant relationship between subjective norm and behavior intention. 3. There were significant linear relationship among knowledge sharing behavior, behavior intention, and organization citizenship behavior. 4. There was a significant mediating effect of organization citizenship behavior. 5. In order to further the knowledge sharing behaviors, some concrete suggestions of food & beverage industry managers, recruitment, and selection were proposed at the end of this study.