Abstract: The present invention provides an intermediation system of transaction that has purchasing indicators to show purchase intent of buyers in transaction through a network. The intermediation system includes first user terminals for requesting the acquisition of information about predetermined products or services, second several user terminals for providing information on products or services which they offer, and an intermediation device for mediating the information between the first user terminals and the second user terminals. The first and second user terminals and the intermediation device are interconnected over a network.