This research proposal presents a research design on the role of key users in ERP implementations. We intend to investigate the following research questions: (1) How do key users function in an ERP implementation project? (2) What factors influence key users' functioning? And how do the factors influence key users' functioning? (3) What are the benefits and impacts of key users? In this proposal, we first review current literature on key users, and then present the theoretical framework of boundary spanner. We also give our research design and data analysis strategy in the last part of the proposal.