Abstract: A laser diode controlling method for a compact disk drive in which light is radiated from a laser diode to a compact disk and a radio frequency (RF) signal is generated by the light reflected from the compact disk, the method includes the steps of converting the light output from the laser diode into a first electrical signal, detecting the level of the RF signal, generating a second electrical signal by adjusting the level of the first electrical signal on the basis of the level of the RF signal, and generating a driving current for the laser diode on the basis of the second electrical signal. Therefore, various types of compact disks can be driven based on the reflectivity thereof with respect to a laser beam.