Electronic auctions have become popular. Recently, multicast technology is changing the Internet environment for e-commerce, and will make available more forms of auctions than were ever practical in the past. This study proposes an online real-time multi-auctions model. The prerequisite of the implementation of this new auction model is the integration of the multicast technology and software agent technology. In this paper, the architecture of the agents that support activities leading to the effectiveness of online real-time multi-auctions is examined. A prototype of the agent, which is built with Java in the multicast environment, is further discussed.