This study tries to explore organizational commitment, knowledge sharing, and organizational citizenship behavior among employees in the Taiwan semiconductor industry. By literature review, this study proposes the research framework and some hypothesis. Empirically we collect the 428 effective subjects from upper, middle, lower teirs in Taiwan semiconductor industry. By structural equation modeling (SEM), this study finds that the knowledge sharing has a full mediation effect on relationship of employee's trust and organizational citizenship behavior. However, knowledge sharing is notable difference on Taiwan semiconductor industry.