This study examines various factors which influence the degree of Participation In B to B e-Marketplace. Based on literature review, six factors such as Information provision, IT infrastructure, trust, aggregation, new customer creation, and matching are identified. To collect the empirical data, survey methodology has been utilized. A total of 32 companies have returned completed responses. The results of analysis show high interdependencies between six factors and the degree of participation in e-Marketplace. In particular, aggregation is found to be the most influential factor. Additional analysis reveals that firms participating highly in e-Marketplace recognize aggregation and new customer creation the most important factors while less participating firms see IT infrastructure more important.