Abstract: Non-commercial university-industry interactions are important ways of academic research achievements of university to serve the society. This paper analyzes the cross-level influence of departmental academic quality on industry engagement behavior of university scholars, by introducing engagement motives of scholars as a mediator. The cross-level analysis of 562 samples shows that: (1) in natural science disciplines, departmental academic quality and the two dimensions of engagement motive are significant positively related to industry engagement, engagement motives have a partially mediating effect on the relationship between departmental academic quality and industry engagement; (2) in humanities and social science disciplines, departmental academic quality only significantly influences research-related motive and has inverted U-shaped relationships with research-related motive and industry engagement: departmental academic quality is positively related to research-related motive and industry engagement in low-quality department while negatively in high-quality department; research-related motive has a partially mediating effect on the relationship between departmental academic quality and industry engagement both in low-quality department and high-quality department. Conclusions of this paper make sense for the improvement of efficiency of university knowledge diffusion.