The study explored how authentic leadership (AL) affected employees' work engagement (WE) both directly and through the mediating role of employees' Psychological Capital (PsyCap). Using a correlation research design, the authors collected valid responses from 304 employees across organizations through a paper survey in Beijing (China). The results showed both authentic leadership and PsyCap positively related to work engagement of employee, and authentic leadership also positively related to PsyCap. A mediation analysis with the use of a boots trapping technique revealed that Psychological Capital mediates the relationship between authentic leadership and work engagement. Our study recommends that organizations could conduct more training programs on authentic leadership development to stimulate leaders to become more authentic, and provides Psychological Capital orientation to employees, to improve employee's work engagement as result in the positively improving the organization performance.