The present invention relates to a novel long-acting palmitic acid-conjugated gonadotropin-releasing hormone (GnRH) derivative and a pharmaceutical composition containing the same. A GnRH derivative of the present invention is expected to greatly contribute, through excellent bioavailability and increased half-life in blood, to a reduction in drug dosing frequency and dosage and the like in the treatment of sex hormone-dependent diseases. Particularly, the GnRH derivative can overcome disadvantages of existing GnRH sustained-release preparations, which have side effects of a residual feeling and pain at the injection site.
