An apparatus and method of controlling emission of a laser beam in an image forming apparatus. The method includes generating a first reference voltage and a second reference voltage corresponding to a normal mode and a toner save mode, supplying one of the first reference voltage and the second reference voltage corresponding to a mode selection signal in a switching manner, generating a first control voltage and second control voltage to control emission of the laser beam, and supplying a drive current corresponding to one of the generated first and second control voltages to a laser diode to control intensity of the laser beam according to the selection mode.