The purpose of this present study was to investigate the influences of motivational work characteristics (knowledge-oriented) and aggregated transformational leadership on the innovativeness of internal revenue service (IRS) officers by using first-line tax officers as the research objects. 374 first-line officers from 47 units of IRS Kaohsiung were sampled. Hierarchical regression analysis and hierarchical linear moderating were used to analyze and verify those hypotheses. The study showed that the knowledge characteristics will influence the self-efficacy of an IRS officer and that self-efficacy can in turn influence individual innovativeness. Additionally, there was a cross-level moderating effect from aggregated transformational leadership and collective efficacy on the relationship between self-efficacy and the individuals’ innovativeness. Conclusion was given, followed by research implications.