While the growth of the e-marketplace such as e-auctions and e-knowledge markets seems phenomenal in recent years, several studies suggest that a large number of Internet users have serious trust concerns, and that winning customers trust is the primary hurdle to continued growth of the e-marketplace. Especially, in the e-marketplace, buyers routinely engage with businesses and individual sellers with whom they have little or no prior interaction, making trust one of the most important issues. In this study, we develop and test a trust-building model for buyers and sellers, respectively. In addition, our analysis provides a theoretical framework that identifies the sources of trust in a market-maker. The results indicate that the buyers trust in a market-maker stems from the characteristics of a market-maker and the website, as well as the customers experience. However, for the seller, only the characteristics of both the market-maker and the website are positively associated with trust in the market-maker.