A method of managing downloading contents in a network system including a terminal device, a management server and a downloading site includes three phases of procedures. In a first phase procedure, the management server receives a request for downloading contents from the terminal device and performs a predetermined registration operation. In a second phase procedure, the management server transmits attribution data corresponding to the contents to be downloaded by the terminal device, the attribution data including information of the downloading site. In a third phase procedure, the terminal device accessed the downloading site in accordance with the information included in the attribution data and downloads the contents.