Abstract: : To establish a n HPLC method for the determination of fludrocortisone acetate related substances. HPLC analysis was performed on YMC Triart C8 ( 4.6 mm×150 mm, 5 μm), with mobile phase of acetonitrile-water by gradient elution, at the monitoring wavelength of 254 nm. The resolution between?main component ?and related impurity met the?requirement , fludrocortisone acetate and its four related substances shows a good linearity in range of 0.20~10 μg/mL ( r=0.999) . The recoveries of the related substances w ere 98.0%~102.0% , with RSDs <10% (n=9)