Despite business-to-government (B2G) electronic auction (e-auction) markets being a way for suppliers to create opportunities for market expansion and for trading activities, the effort to understand the behaviour of suppliers participating in these markets has been lacking. Low supplier participation has been a major problem in Thai e-auction markets. In this paper, we propose a framework to explain suppliers’ intention to participate, and the level of participation in B2G e-auction markets. We posit that suppliers’ participation depends on organizational motivation, and their capabilities. The conceptual framework draws from the Motivation-Ability Framework, Transaction Cost Theory, Institutional Theory, and Resource-Based Theory. It proposes that three key constructs - efficiency motive, legitimacy motive, and organizational capabilities influence suppliers’ intention to participate as well as their participation level in B2G e-auction markets. The conceptual framework may be useful to better understand the key reasons for suppliers to participate in B2G e-auction markets. We also provide rationale for each of the Proceedings of SIG GlobDev’s First Annual Workshop, Paris, France December 13th 2008 Dolpanya et al. Suppliers’ Participation in B2G E-Auctions proposed constructs by drawing on our understanding of the Thai electronic auction market as well as the existing literature.