A portable device which is capable of communicating with an external device and a control method thereof are discussed. A method for transmitting user input of a portable device includes detecting navigating input in a navigation mode for controlling an external device which is connected by a network, wherein the external device displays displayable content and the navigating input is for navigating the displayable content which includes at least one input box, transmitting a control signal corresponding to the detected navigating input to the external device, displaying an indicator which indicates capability of mode switching from the navigation mode to a user input mode, initiating the user input mode by displaying the input box which is extracted from the displayable content when user input for mode switching is detected, and transmitting user input which is received through the displayed input box.