A portable terminal and a method for displaying an idle screen of the portable terminal are provided. The terminal includes a Radio Frequency (RF) unit for receiving signal from an external, a memory for storing a plurality of image elements comprising an idle screen image (IDLE_Img), a key input unit for generating a key input signal, a display unit for displaying the IDLE_Img, a battery for supplying necessary power to a terminal, and a controller for controlling receiving/transmitting signals between the respective components comprising the RF unit, the memory, the key input unit, the display unit and the battery, and for controlling the IDLE_Img to be displayed differently from a preset image according to system internal information parameter (Sys_Info) generated in response to changes of the respective components.