Since the outbreak of COVID-19 pandemic, telework has been widely adopted as a new HR practice by modern organizations, it has enormous effects on an organization and its members. However, the existing studies have reported mixed results of positive and negative effects of telework on employee attitudes and performances. For example, some studies showed positive effects that employees may develop autonomy beyond the restriction of time and space, while others revealed negative ones that telework may hinder employee commitment to job. The present study, by first constructing effectiveness of telework with three dimensions, - usefulness, easiness, and pleasure - attempts to explore the mechanism in which telework affects employee attitudes and behaviors with 200 samples. Our results show that effectiveness of telework has a positive effect on organizational citizenship behavior (OCB), that employees’ psychological empowerment mediates the relationship, and that transformational leadership moderates the relationship between effectiveness of telework and psychological empowerment. Presenting theoretical contributions, practical implications, study limitations, and future research directions, the present study contributes to scholars and managers’ further understanding of telework.