PURPOSE: An advertisement display method in a wireless mobile terminal using a file downloading time is provided to reproduce and screen-output an advertisement message close to the time required for the downloading a high capacity file to a wireless mobile terminal. CONSTITUTION: When a mobile terminal accesses an Internet network and selects a desired file from a site holding various file(S10), a file select signal is transmitted to a Web server. The Web server transmits a message requesting a confirmation for downloading a data on the basis of the file select signal, and the confirmation request message is inputted to a controller. The controller displays the confirmation request message content on a display unit. When the user clicks 'OK' over the text content displayed on the display unit, the OK clock signal is transmitted to the Web server. The Web server fetches the user's desired file from the site and transmits it to a mobile communication network(S12). The file is stored in a memory unit and the controller calculates a time required for downloading it in consideration of the size of the file and the speed of the current downloading(S14). The controller extracts an advertisement message having a reproduction time most close to the calculated time required for downloading among various advertisement message. The controller transmits the advertisement message to a reproduction processing unit and the reproduction processing reproduces the advertisement message and displays it on the display unit. Accordingly, the advertisement is displayed on the display unit.