Abstract: Residual amount of fenbutatin oxide in vegetable sample was determined by GC with flame photometric detector (FPD).The sample was extracted by acetone-acetic acid (1+1) solution and n-hexane,and derivatized with ethyl magnesium bromide-diethyl ether solution.The derivatized product was purified and concentrated on silica column with n-hexane-dichloromethane mixture (4+1) as eluant.The eluate from column was evaporated by N2-blowing and made up to 1 mL,with n-hexane,which was used for GC analysis.External standard calibration was adopted in the determination.Linear relationship between values of peak area and mass concentration of fenbutatin oxide were obtained in the range of 0.2-2.0 mg·L-1,with detection limit (3S/N) of 0.1 mg·kg-1.Test for recovery was made by standard addition method,giving results in the range of 76.9%-88.8%.Values of RSD′s (n=6) found were in the range of 3.46%-9.34%.