A method for writing a spiral reference servo signal suitable for a self-servo writing method in a hard disk drive includes writing a first reference pattern in an end direction of a spiral reference servo signal writing concentrically on the disk; writing a spiral reference servo signal on a current spiral track from a reference writing start position of the current spiral track; detecting a moving angle of a head to the first reference pattern, which corresponds to a distance from the reference writing start position to a reference writing end position of the spiral reference servo signal in the case that thermal expansion of the disk does not exist; compensating for a driving speed of the head with reference to the detected moving angle of the head; and writing the spiral reference servo signal on a next spiral track at a compensated driving speed of the head.