Abstract: A system for purchasing products through bidding online includes an application server (13), a corporation website (12), a database (15), a plurality of client computers (10) and a plurality of supplier computers (17). The application server includes a supplier data management module (131) for maintaining basic information on suppliers and their products, and predetermining a plurality of selected suppliers according to information on products to be purchased; a price inquiring/quoting/price negotiating management module (132) for inquiring of prices, receiving quotations from selected suppliers, negotiating prices, and generating price-related records; an online bidding management module (133) for opening a bid, comparing bidding results to determine a winning supplier, and generating bid-related records; a contract management module (134) for signing and maintaining of procurement contracts. A method for purchasing products through bidding online is also disclosed.