Disclosed is a method of compressing and decompressing an executable file in a mobile communication terminal capable of improving a compression mode of an executable file necessary for an operation of the mobile communication terminal to reduce a booting time of the terminal and to smoothly carrying out a wireless upgrade service. The method of the invention divides storage spaces in which executable files are stored into plural areas depending on properties of the executable files using a scatter loading file and selectively compressing each of the areas.