Entecavir is a potent and selective guanosine analogue that has demonstrated a significant antiviral efficacy against hepatitis B virus (HBV). The aim of this study was to evaluate the safety and pharmacokinetic profile after a single dose of entecavir 1 mg administration in Korean healthy male subjects. Eight volunteers were enrolled. After a single dose of 1 mg entecavir was orally administered, blood samples were collected at specific time intervals from 0-168 hours. The plasma concentrations of entecavir were determined by LC-MS/MS. The pharmacokinetic parameters were determined from the plasma concentration-time profiles. The mean values for $AUC_{last}$ and $AUC_{inf}$ were $14.84{pm}7.81ng{cdot}hr/mL$ and $20.71{pm}8.80ng{cdot}hr/mL$, respectively. The mean value for $C_{max}$ was $9.19{pm}4.91ng/ml$ and median value for $t_{max}$ was 0.58 hr. No adverse events were reported by subjects or found on analysis of vital signs or laboratory tests. The results are suggested to be useful in clinical trials of entecavir in Korean subject including bioequivalence study.