A simple and effective high-performance liquid chromatography with ultraviolet detection (HPLC-UV) method was established to determine entecavir optical isomers. With 3 chiral carbon atoms, entecavir had 7 optical isomers, including 6 diastereoisomers and 1 enantiomer. The separations were performed on a Symmetrix ODS-AQ C18 column (4.6 mm×250 mm, 5 µm) and a Daicel CHIRALPAK AD column (4.6 mm×250 mm,10 µm), respectively. The detection wavelength was set at 254 nm.The limit of detection (LOD) and the limit of quantification (LOQ) of diastereoisomers (diastereoisomer-1, diastereoisomer-2, diastereoisomer-3) were 0.0371, 0.0376, 0.0377, and 0.124, 0.125, 0.126 µg/mL, respectively. The LOD and LOQ of enantiomer were 0.14 and 0.46 µg/mL, respectively. The precision was within 0.36%, 0.44%, 1.04%, and 0.67% for diastereoisomer-1, diastereoisomer-2, diastereoisomer-3, and enantiomer, respectively. The recoveries of enantiomers ranged from 98.4% to 100.5%. The method could be applied to control the quality of entecavir.