E-Marketplace is a man-made profit center with emergent customer requirements. This emergence nature poses many difficulties for e-marketplace to satisfy its customers and thus affects its survivability and competitiveness. To challenge this issue, this paper has introduced a novel emergent e-marketplace model, and analyzed and quantified the emergent properties of e-marketplace from simple ESMs to very large complex electronic intermediary EIMs. The measurement models developed in this paper are very useful for producing dynamic interaction records appropriate for further simulation model of e-marketplaces. © Springer-Verlag Berlin Heidelberg 2003.