Abstract: This specification discloses a web trading method for reducing stocking costs. This is achieved mainly by establishing a real-time material supply trading procedure with a materials supplier through a web trading system. The invention includes the following steps. A forecast order containing a material forecast demand is sent from a purchaser to a materials supplier. The materials supplier temporarily stores materials according to the material forecast demand in the storage of the materials supplier. The purchaser can timely send out a real-time demand order containing material real-time demands to the materials supplier according to the production demands to ask the materials supplier to provide the material real-time demands accordingly. At the moment, the materials supplier retrieves the real-time material quantities required in the real-time demand order from its storage and sends them to the purchaser.