Provided are a method of improving a recording performance of a hard disk drive (HDD) by controlling write strength according to a flying height of a head and a computer-readable recording medium having recorded thereon a computer-readable program suitable for the method. The method of controlling write strength of the HDD includes calculating the flying height of the head before starting a recording operation and controlling the write strength according to the calculated flying height. Accordingly, optimal writing can be performed by the write strength according to the head flying height.