A search system, an information-providing system and an information search method. "Response information" such as a checkmark for indicating exclusion and a message added by a customer terminal and "additional information" added by a supplier terminal to a commodity retrieved by a search for data in a commodity database of a server based on search criteria input through the customer terminal are associated and stored with "session-specific information" in a session-specific database. When the supplier terminal accesses the server, the "response information" input by the customer terminal is transferred to the supplier terminal. When the customer terminal accesses the server, the "additional information" added by the supplier terminal is transferred to the customer terminal.