This article uses the 2014 Chinese Non-profit Employee Survey (CNES) to empirically investigate the factors that drive employees to leave the non-profit sector. Findings have shown that salary level and mission attachment impact employees' intent to leave and that the two factors are moderated by the length of work experience. For employees with fewer than five years' work experience, mission attachment has a negative impact on the intent to switch sectors. For employees with over five years' experience, salary level is positively associated with the intention to leave. This study also identifies salary gap as a mediator to explain research findings and offers implications for the sustainable development of human resources in China's non-profit sector.