A high performance liquid chromatographic method for the determination of phenoxyacetic acid and 2,4-dichlorophroxyacetic acid in environnmental waters was described.Phenoxyacetic acid and 2, 4-dichioropheroxyacetic acid in sample were enriched on Sep-Pak C18 column,and methanol was employed as elutent.The shim-pack CLC ODS (150mm×6.0mm i.d.) column was used as separation column at 40°C and eluted with methanol-water (9:1,V/V)(pH 3.0) at flow rate of 1.0mL/min,the detection wavelength was 275 nm.The recoveries of the two compounds were>98%.The detection limit was 0.04mg/L.