In the past, most studies in innovation management have adopted the creator's perspective. Few researchers have adopted a user's or gatekeeper's view. Furthermore, research on gatekeeping in innovation, R&D management, and creativity seldom focus directly on the gatekeeping itself. To fill this gap, this study tries to clarify exactly what gatekeeping is. The study follows the logic of Lewin's gatekeeping theory and introduces the evolution perspective. It also integrates the technology gatekeeper, Csikszentmihaly's system model, and institutional theory to examine gatekeeping in selecting creative ideas. This paper proposes five key factors in the gatekeeping construct: the ability to earn creators' trust, the ability to raise creators' motivation, the selection of professional abilities, standards of evaluation, and the degree of interaction. Then, following Lewin's gatekeeping theory, this study classifies these five factors into two dimensions: the gatekeeping capabilities and institutional routines. Finally, on the basis of this theoretical model and the procedure from Hinkin (1998), this study develops and tests a questionnaire on gatekeeping of creative ideas inside project teams. The results show that the theoretical model is reasonable and that the questionnaire has fair reliability and validity. This research can serve as a foundation for future innovation studies on gatekeeping of creative ideas. It also serves to remind the managers of the importance of gatekeeping and provides a model for managing innovations.