This thesis presents a Web services implementation of the infrastructure for e-Marketplaces based on e-Marketplace business patterns. Business patterns implemented by the infrastructure include User-to-Business, User-to-Online Buying, User-to-User, and Business-to-Business integration. The implementation of the User-to-Business pattern provides for all non-commercial user transactions with the e-Marketplace, including the registration processes, aggregating the e-Marketplace catalog with product and service offers, response to requests for quote, and purchase order checking and processing. The implementation of the User-to-Online Buying pattern provides for all commercial transactions that a user may conduct with the e-Marketplace, including catalog-based buying, contract-based buying, auction bidding, exchange bid offering, and the publication of requests for quote. The implementation of the User-to-User pattern supports e-Marketplace user communication. The implementation of the Business-to-Business integration pattern enables commerce systems of the suppliers and procurement systems of the buyers to integrate with the e-Marketplace to conduct commerce and non-commerce transactions. <br><br> The implemented e-Marketplace infrastructure provides a foundation for building concrete e-Marketplaces, by e-Marketplace builders, to present the e-Marketplace functionalities to the end users such as e-Marketplace administrators and traders. The infrastructure is implemented using Web services technology to provide system-independent accessibility to clients of concrete e-Marketplaces that are built on the infrastructure. The infrastructure implements the business patterns in the form of groups of collaborating Web services.