Abstract: A method of optimal power calibration adapted to rewritable or recordable disks is disclosed. In addition to an original power calibration area (PCA) in the inner track of a disk, another rearranged PCA is allocated in the lead-out area of the outmost track. Two optimal power calibration processes are performed on both of the power calibration areas allocated on the inner and outmost tracks to respectively derived optimal recording powers. A relation curve is established by using these two optimal recording powers that this relation curve describes the relationships between the optimal recording powers of the recording positions and the distances from these recording positions to the center of the optical storage disk. Required optimal recording power of any recording position can be derived from the relation curve while performing data recording operations.