Abstract: A method of capillary electrophoresis combined with indirect UV detection was developed for the determination of glyphosate,glufosinate,and their metabolites (aminomethylphosphonic acid and 3-methylphosphinicopropionic acid). The sample was mixed with ammonium acetate solution of 25 mmol·L-1 and the target compounds in the mixture were extracted with SAX cartridge solid phase extraction column. The eluent was separated by capillary electrophoresis with o-phosphate-DL-threonine as internal standard. UV detection was made at the wavelength of 214 nm. The linearity ranges of glyphosate,glufosinate,aminomethylphosphonic acid and 3-methylphosphinicopropionic acid were 0.10-20.0 mg·L-1. The detection limits were 0.22,0.30,0.18,0.03 mg·L-1,respectively. Recovery rates measured by standard addition method were in the range of 82.1%-108%.