Abstract: Enantiomers of Fluazifop-p-butyl were successfully separated by using the chiral chromatographic column of Nucleosil chiral-2 (column temp.10 ℃) and the mobile phase composed of n-heptane,iso-propyl alcohol and trifluoroacetic acid mixed in the ratio of 99.3+0.5+0.2 by volume.The flow-rate of the mobile phase used was 0.6 mL·min-1,and UV-detection at 273 nm was adopted in the measurements.Under optimum chromatographic conditions of separation,linear relationship between the peak area and concentration of the R-isomer was obtained corresponding to the linear regression equation A=(236.3 ρ+1.94)×100 with a correlation coefficient of 0.999 1.On this basis,the R-isomer of fluazifor-p-butyl was determined.