Abstract: A mobile terminal and a method for controlling operation of the mobile terminal are provided. In the method, a webpage that requires input of an authentication number for user authentication is displayed and a message including an authentication number is then received upon requesting an authentication number through the webpage. The authentication number is extracted from the message and the extracted authentication number is input to the webpage to allow the authentication process to be performed. Accordingly, it is possible to quickly and easily perform login authentication information input or the user authentication process using the mobile terminal.