The enantiomers of five amino acids (alanine, valine, threonine, leucine and phenylalanine) could be separated by gas chromatography with optically active (S)-5-isopropyll-$N^3$-phenyl-2-thiohydantoinic stationary phase, which prepared from L-valine and phenylisothiocyanate. Gas chromatographic separations on methylesterificated and N-trifluoroacetylated amino acids have been conducted in isothermal at several column temperatures (180~190, 200, $210^{circ}C$). The separation factors were 1.29 (alanine, $190^{circ}C$), 1.35 (valine, $190^{circ}C$), 1.33 (threonine, $190^{circ}C$), 1.17 (leucine, $190^{circ}C$) and 1.05 (phenylalanine, $190^{circ}C$) and D-isomers eluted prior to L-isomers in every instance. The result of this experiment shows that this stationary phase can be used for the separation of the other amino acids enantiomers.