Provided are a method and apparatus for performing a writing test using charge pumps in an optical disk reproducing/recording apparatus. In the apparatus for performing the writing test, an optimum power control (OPC) determining unit determines a phase of a radio frequency signal using a reference voltage, and generates a corresponding OPC voltage; an analog-to-digital converter (ADC) unit converts the OPC voltage into a digital signal; and a micom controls a power control unit according to the digital signal, to appropriately control laser power.