Method and apparatus for writing and reading an optical recording medium

An apparatus for writing on and reading an overwritable optical disk comprises an identifier detector (119) that identifies a recording condition in the sector to be overwritten, and a delay time controller circuit (106) that sets a variation range of the start point for writing according to the recording condition. The record timing of the modulated data signal (105) is changed at random within the set variation range when overwriting the sector of the optical disk (113).