The pharmacokinetics of YH439 and its metabolites were investigated after oral administration of YH439 to rats to investigate the food effect. After oral administration of YH439, its metabolites, M4 and M5 were detected in plasma. YH439 was not detected in the plasma for both fasted and fed rats for all doses studied. The pharmacokinetic parameters of the metabolites were not affected by food at all doses studied. The results of this study indicated that there are no significant food effects on the pharmacokinetics of YH439 and its metabolites in rats.