In a contents retrieval system, when a publisher terminal uploads shared contents to a shared server, the shared server stores the shared contents in a contents area of a contents database, a partial data formation section forms partial data specifying the shared contents and stores the formed partial data in a partial data area, and a URL generation section forms a URL linked to the shared contents and stores the URL in a URL area. When the contents retrieval section receives partial data from the retriever terminal, it collates the received partial data with the partial data in partial data area of the contents database. When the partial data is found, the contents retrieval section replies a URL of the corresponding shared contents to the retriever terminal.