Abstract: A method and apparatus for accomplishing an OPC (optimal power calibration) at a test area secured in data recording area of a writable optical recording medium and detecting an optimal writing power appropriate to the test area. The method searches for a marginal area adjacent to a data section recorded on an optical recording medium, records test data on the marginal area discovered in the searching step while changing a writing power; and reproduces the test data recorded on the marginal area and determining an optimal writing power based upon the characteristics of the reproduction signal. The method and system can reduce delay time required to move an optical pickup inward and outward to accomplish the OPC operation and enhances writing characteristics since an optimal writing power is obtained from a test area which is very close to data area to record input data.